1100+ MCQs On Solar System

 Solar System

1. Which planet is known as the "Red Planet"?  

a) Venus  

b) Mars ✅  

c) Jupiter  

d) Mercury  

Explanation: Mars appears red due to iron oxide on its surface.

2. The largest planet in our Solar System is:  

a) Earth  

b) Saturn  

c) Jupiter ✅  

d) Neptune  

Explanation: Jupiter is the largest planet with a diameter of about 142,984 km.

3. Which planet is closest to the Sun?  

a) Mercury ✅  

b) Venus  

c) Earth  

d) Mars  

Explanation: Mercury is the innermost planet.

4. The asteroid belt lies between:  

a) Earth and Mars  

b) Mars and Jupiter ✅  

c) Jupiter and Saturn  

d) Saturn and Uranus  

Explanation: The asteroid belt is located between Mars and Jupiter.

5. Which planet is called the "Morning Star" or "Evening Star"?  

a) Venus ✅  

b) Mercury  

c) Mars  

d) Saturn  

Explanation: Venus is visible at dawn or dusk.

6. Which planet has the fastest rotation?  

a) Earth  

b) Jupiter ✅  

c) Saturn  

d) Neptune  

Explanation: Jupiter rotates once in about 10 hours.

7. The planet with the most prominent ring system is:  

a) Uranus  

b) Saturn ✅  

c) Neptune  

d) Jupiter  

Explanation: Saturn’s rings are the most visible.

8. Which planet is tilted on its side at about 98 degrees?  

a) Neptune  

b) Uranus ✅  

c) Saturn  

d) Jupiter  

Explanation: Uranus rotates almost on its side.

9. The dwarf planet reclassified in 2006 is:  

a) Ceres  

b) Pluto ✅  

c) Eris  

d) Haumea  

Explanation: Pluto was reclassified by the IAU.

10. Which planet is known for the Great Red Spot?  

a) Saturn  

b) Jupiter ✅  

c) Neptune  

d) Mars  

Explanation: The Great Red Spot is a storm on Jupiter.

11. Which planet is called Earth’s twin due to similar size?  

a) Venus ✅  

b) Mars  

c) Mercury  

d) Neptune  

Explanation: Venus is similar in size and mass to Earth.

12. Which planet has the longest day compared to its year?  

a) Mercury ✅  

b) Venus  

c) Earth  

d) Mars  

Explanation: Mercury’s rotation is very slow compared to its orbit.

13. The coldest planet in the Solar System is:  

a) Neptune ✅  

b) Uranus  

c) Saturn  

d) Pluto  

Explanation: Neptune has the lowest average temperature.

14. Which planet is known as the "Blue Planet"?  

a) Earth ✅  

b) Neptune  

c) Uranus  

d) Venus  

Explanation: Earth appears blue due to water.

15. Which planet has the highest mountain in the Solar System?  

a) Earth  

b) Mars ✅  

c) Venus  

d) Mercury  

Explanation: Olympus Mons on Mars is the tallest volcano.

16. Which planet has the most moons?  

a) Jupiter ✅  

b) Saturn  

c) Uranus  

d) Neptune  

Explanation: Jupiter has the highest confirmed moon count.

17. Which planet is known as the "Ice Giant"?  

a) Uranus ✅  

b) Neptune ✅  

c) Saturn  

d) Jupiter  

Explanation: Uranus and Neptune are ice giants.

18. Which planet is the hottest in the Solar System?  

a) Mercury  

b) Venus ✅  

c) Earth  

d) Mars  

Explanation: Venus has a runaway greenhouse effect.

19. Which planet has a day longer than its year?  

a) Venus ✅  

b) Mercury  

c) Earth  

d) Mars  

Explanation: Venus rotates very slowly.

20. Which planet is called the "Gas Giant"?  

a) Jupiter ✅  

b) Saturn ✅  

c) Uranus  

d) Neptune  

Explanation: Jupiter and Saturn are gas giants.

21. Which planet has methane clouds giving it a blue color?  

a) Neptune ✅  

b) Uranus  

c) Saturn  

d) Jupiter  

Explanation: Methane absorbs red light, making Neptune blue.

22. Which planet has the shortest year?  

a) Mercury ✅  

b) Venus  

c) Earth  

d) Mars  

Explanation: Mercury completes orbit in 88 days.

23. Which planet has the slowest rotation?  

a) Venus ✅  

b) Mercury  

c) Earth  

d) Mars  

Explanation: Venus rotates once in 243 Earth days.

24. Which planet is known as the "Evening Star"?  

a) Venus ✅  

b) Mars  

c) Mercury  

d) Saturn  

Explanation: Venus shines brightly at dusk.

25. Which planet has the largest volcano?  

a) Mars ✅  

b) Earth  

c) Venus  

d) Mercury  

Explanation: Olympus Mons is the largest volcano.

26. Which planet has the thickest atmosphere?  

a) Venus ✅  

b) Earth  

c) Mars  

d) Mercury  

Explanation: Venus has a dense CO₂ atmosphere.

27. Which planet has the strongest magnetic field?  

a) Jupiter ✅  

b) Saturn  

c) Earth  

d) Neptune  

Explanation: Jupiter’s magnetic field is strongest.

28. Which planet has the largest moon?  

a) Jupiter ✅  

b) Saturn  

c) Earth  

d) Neptune  

Explanation: Ganymede is the largest moon.

29. Which planet has rings besides Saturn?  

a) Jupiter ✅  

b) Uranus ✅  

c) Neptune ✅  

d) All of the above ✅  

Explanation: All gas giants have rings.

30. Which planet is known as the "Morning Star"?  

a) Venus ✅  

b) Mercury  

c) Mars  

d) Saturn  

Explanation: Venus is visible at dawn.

31. Which planet has the Great Dark Spot?  

a) Neptune ✅  

b) Uranus  

c) Saturn  

d) Jupiter  

Explanation: Neptune has a storm called the Great Dark Spot.

32. Which planet has the highest wind speeds?  

a) Neptune ✅  

b) Jupiter  

c) Saturn  

d) Uranus  

Explanation: Neptune’s winds exceed 2,000 km/h.

33. Which planet has the largest ring system?  

a) Saturn ✅  

b) Jupiter  

c) Uranus  

d) Neptune  

Explanation: Saturn’s rings are most extensive.

34. Which planet is known as the "Water Planet"?  

a) Earth ✅  

b) Mars  

c) Venus  

d) Neptune  

Explanation: Earth has abundant liquid water.

35. Which planet has the most elliptical orbit?  

a) Mercury ✅  

b) Pluto  

c) Mars  

d) Earth  

Explanation: Mercury’s orbit is highly elliptical.

36. Which planet is the densest?  

a) Earth ✅  

b) Jupiter  

c) Saturn  

d) Neptune  

Explanation: Earth has the highest density.

37. Which planet has the shortest day?  

a) Jupiter ✅  

b) Saturn  

c) Neptune  

d) Uranus  

Explanation: Jupiter rotates in about 10 hours.

38. Which planet has the longest year?  

a) Neptune ✅  

b) Uranus  

c) Saturn  

d) Jupiter  

Explanation: Neptune takes 165 Earth years to orbit the Sun.

39. Which planet has the largest storm system?  

a) Jupiter ✅  

b) Neptune  

c) Saturn  

d) Uranus  

Explanation: Jupiter’s Great Red Spot is the largest storm.

40. Which planet has the most tilted axis?  

a) Uranus ✅  

b) Neptune  

c) Saturn  

d) Jupiter  

Explanation: Uranus has a tilt of 98 degrees.

41. Which planet is known as the "Greenhouse Planet"?  

a) Venus ✅  

b) Earth  

c) Mars  

d) Mercury  

Explanation: Venus has a runaway greenhouse effect.

42. Which planet has the most satellites?  

a) Jupiter ✅  

b) Saturn  

c) Uranus  

d) Neptune  

Explanation: Jupiter has the most confirmed moons.

43. Which planet has the largest equatorial bulge?  

a) Jupiter ✅  

b) Saturn  

c) Earth  

d) Neptune  

Explanation: Jupiter’s fast rotation causes bulging.

44. Which planet has the most extreme seasons?  

a) Uranus ✅  

b) Neptune  

c) Saturn  

d) Earth  

Explanation: Uranus’s tilt causes extreme seasons.

45. Which planet has the largest core?  

a) Jupiter ✅  

b) Saturn  

c) Earth  

d) Neptune  

Explanation: Jupiter has the largest core.

46. Which planet has the most volcanic activity?  

a) Earth ✅  

b) Mars  

c) Venus  

d) Mercury  

Explanation: Earth is geologically active.

47. Which planet has the most eccentric orbit?  

a) Pluto ✅  

b) Mercury  

c) Mars  

d) Earth  

Explanation: Pluto’s orbit is highly eccentric.

48. Which planet has the largest gravitational pull?  

a) Jupiter ✅  

b) Saturn  

c) Earth  

d) Neptune  

Explanation: Jupiter’s gravity is strongest.

49. Which planet has the most tilted orbit?  

a) Pluto ✅  

b) Mercury  

c) Mars  

d) Earth  

Explanation: Pluto’s orbit is tilted compared to others.

50. Which planet is known as the "Third Rock from the Sun"?  

a) Earth ✅  

b) Mars  

c) Venus  

d) Mercury  

Explanation: Earth is the third planet from the Sun.

51. Which planet is the smallest in the Solar System?  

a) Mercury ✅  

b) Mars  

c) Venus  

d) Pluto  

Explanation: Mercury is the smallest planet by diameter and mass.

52. Which planet is the brightest in the night sky after the Moon?  

a) Venus ✅  

b) Jupiter  

c) Mars  

d) Saturn  

Explanation: Venus is the brightest planet visible to the naked eye.

53. Which planet has the slowest orbital speed around the Sun?  

a) Neptune ✅  

b) Uranus  

c) Saturn  

d) Jupiter  

Explanation: Neptune takes 165 years to complete one orbit.

54. Which planet is known as the "Twin of Neptune"?  

a) Uranus ✅  

b) Saturn  

c) Jupiter  

d) Earth  

Explanation: Uranus and Neptune are similar in size and composition.

55. Which planet has the most tilted orbit compared to the ecliptic?  

a) Pluto ✅  

b) Mercury  

c) Mars  

d) Earth  

Explanation: Pluto’s orbit is tilted about 17° to the ecliptic.

56. Which planet is the densest in the Solar System?  

a) Earth ✅  

b) Jupiter  

c) Saturn  

d) Neptune  

Explanation: Earth has the highest density at 5.51 g/cm³.

57. Which planet has the shortest rotation period?  

a) Jupiter ✅  

b) Saturn  

c) Neptune  

d) Uranus  

Explanation: Jupiter rotates once in about 10 hours.

58. Which planet is known as the "Evening Star"?  

a) Venus ✅  

b) Mars  

c) Mercury  

d) Saturn  

Explanation: Venus is visible at dusk.

59. Which planet has the most extreme greenhouse effect?  

a) Venus ✅  

b) Earth  

c) Mars  

d) Mercury  

Explanation: Venus’s thick CO₂ atmosphere traps heat.

60. Which planet is the farthest from the Sun?  

a) Neptune ✅  

b) Uranus  

c) Pluto  

d) Saturn  

Explanation: Neptune is the farthest recognized planet.

61. Which planet has the largest equatorial bulge due to rotation?  

a) Jupiter ✅  

b) Saturn  

c) Earth  

d) Neptune  

Explanation: Jupiter’s rapid rotation causes bulging at the equator.

62. Which planet has the longest rotation period?  

a) Venus ✅  

b) Mercury  

c) Earth  

d) Mars  

Explanation: Venus rotates once in 243 Earth days.

63. Which planet has the most tilted axis?  

a) Uranus ✅  

b) Neptune  

c) Saturn  

d) Jupiter  

Explanation: Uranus has a tilt of 98°.

64. Which planet is known as the "Blue Planet"?  

a) Earth ✅  

b) Neptune  

c) Uranus  

d) Venus  

Explanation: Earth appears blue due to oceans.

65. Which planet has the largest storm system?  

a) Jupiter ✅  

b) Neptune  

c) Saturn  

d) Uranus  

Explanation: Jupiter’s Great Red Spot is the largest storm.

66. Which planet has the highest wind speeds?  

a) Neptune ✅  

b) Jupiter  

c) Saturn  

d) Uranus  

Explanation: Neptune’s winds exceed 2,000 km/h.

67. Which planet has the most extreme seasons?  

a) Uranus ✅  

b) Neptune  

c) Saturn  

d) Earth  

Explanation: Uranus’s tilt causes extreme seasonal changes.

68. Which planet has the shortest year?  

a) Mercury ✅  

b) Venus  

c) Earth  

d) Mars  

Explanation: Mercury completes orbit in 88 days.

69. Which planet has the longest year?  

a) Neptune ✅  

b) Uranus  

c) Saturn  

d) Jupiter  

Explanation: Neptune takes 165 Earth years to orbit the Sun.

70. Which planet is known as the "Gas Giant"?  

a) Jupiter ✅  

b) Saturn ✅  

c) Uranus  

d) Neptune  

Explanation: Jupiter and Saturn are classified as gas giants.

71. Which planet is called the "Morning Star"?  

a) Venus ✅  

b) Mercury  

c) Mars  

d) Saturn  

Explanation: Venus is visible at dawn, hence called Morning Star.

72. Which planet has the most eccentric orbit among the major planets?  

a) Mercury ✅  

b) Mars  

c) Earth  

d) Neptune  

Explanation: Mercury’s orbit is highly elliptical compared to others.

73. Which planet is known as the "Blue Giant"?  

a) Neptune ✅  

b) Uranus  

c) Saturn  

d) Jupiter  

Explanation: Neptune appears blue due to methane in its atmosphere.

74. Which planet has the shortest distance from Earth at opposition?  

a) Mars ✅  

b) Venus  

c) Mercury  

d) Jupiter  

Explanation: Mars comes closest to Earth during opposition.

75. Which planet has the thickest atmosphere among terrestrial planets?  

a) Venus ✅  

b) Earth  

c) Mars  

d) Mercury  

Explanation: Venus has a dense CO₂ atmosphere.

76. Which planet has the largest tilt of orbit relative to the Sun?  

a) Pluto ✅  

b) Mercury  

c) Mars  

d) Earth  

Explanation: Pluto’s orbit is tilted about 17°.

77. Which planet has the most volcanic moon?  

a) Jupiter ✅  

b) Saturn  

c) Uranus  

d) Neptune  

Explanation: Io, a moon of Jupiter, is volcanically active.

78. Which planet has the most tilted magnetic field?  

a) Uranus ✅  

b) Neptune  

c) Saturn  

d) Jupiter  

Explanation: Uranus’s magnetic field is tilted compared to its axis.

79. Which planet is known as the "Evening Star"?  

a) Venus ✅  

b) Mars  

c) Mercury  

d) Saturn  

Explanation: Venus shines brightly at dusk.

80. Which planet has the largest storm system after Jupiter?  

a) Neptune ✅  

b) Saturn  

c) Uranus  

d) Earth  

Explanation: Neptune has the Great Dark Spot.

81. Which planet has the most extreme greenhouse effect?  

a) Venus ✅  

b) Earth  

c) Mars  

d) Mercury  

Explanation: Venus’s atmosphere traps heat effectively.

82. Which planet has the shortest orbital period?  

a) Mercury ✅  

b) Venus  

c) Earth  

d) Mars  

Explanation: Mercury completes orbit in 88 days.

83. Which planet has the longest orbital period?  

a) Neptune ✅  

b) Uranus  

c) Saturn  

d) Jupiter  

Explanation: Neptune takes 165 years to orbit the Sun.

84. Which planet is known as the "Gas Giant"?  

a) Jupiter ✅  

b) Saturn ✅  

c) Uranus  

d) Neptune  

Explanation: Jupiter and Saturn are gas giants.

85. Which planet has the most tilted axis?  

a) Uranus ✅  

b) Neptune  

c) Saturn  

d) Jupiter  

Explanation: Uranus rotates almost on its side.

86. Which planet has the most moons among terrestrial planets?  

a) Earth ✅  

b) Mars  

c) Mercury  

d) Venus  

Explanation: Earth has one moon, Mars has two, others have none.

87. Which planet has the largest moon in the Solar System?  

a) Jupiter ✅  

b) Saturn  

c) Earth  

d) Neptune  

Explanation: Ganymede, Jupiter’s moon, is the largest.

88. Which planet has the most tilted orbit among gas giants?  

a) Uranus ✅  

b) Neptune  

c) Saturn  

d) Jupiter  

Explanation: Uranus has a unique tilt.

89. Which planet is known as the "Water Planet"?  

a) Earth ✅  

b) Mars  

c) Venus  

d) Neptune  

Explanation: Earth has abundant liquid water.

90. Which planet has the most tilted orbit among dwarf planets?  

a) Pluto ✅  

b) Ceres  

c) Eris  

d) Haumea  

Explanation: Pluto’s orbit is tilted compared to others.

91. Which planet has the largest equatorial bulge?  

a) Jupiter ✅  

b) Saturn  

c) Earth  

d) Neptune  

Explanation: Jupiter’s rapid rotation causes bulging.

92. Which planet has the most tilted magnetic field among ice giants?  

a) Uranus ✅  

b) Neptune  

c) Saturn  

d) Jupiter  

Explanation: Uranus’s magnetic field is tilted.

93. Which planet has the most tilted orbit among terrestrial planets?  

a) Mercury ✅  

b) Venus  

c) Earth  

d) Mars  

Explanation: Mercury’s orbit is highly tilted.

94. Which planet has the most tilted axis among terrestrial planets?  

a) Earth ✅  

b) Mars  

c) Venus  

d) Mercury  

Explanation: Earth’s tilt is 23.5°, causing seasons.

95. Which planet has the most tilted orbit among gas giants?  

a) Uranus ✅  

b) Neptune  

c) Saturn  

d) Jupiter  

Explanation: Uranus’s orbit is tilted.

96. Which planet has the most tilted axis among dwarf planets?  

a) Pluto ✅  

b) Ceres  

c) Eris  

d) Haumea  

Explanation: Pluto’s axis is tilted.

97. Which planet has the most tilted orbit among moons?  

a) Triton ✅  

b) Ganymede  

c) Titan  

d) Io  

Explanation: Triton, Neptune’s moon, has a retrograde orbit.

98. Which planet has the most tilted axis among moons?  

a) Titan ✅  

b) Ganymede  

c) Io  

d) Europa  

Explanation: Titan has a tilted axis.

99. Which planet has the most tilted orbit among asteroids?  

a) Ceres ✅  

b) Vesta  

c) Pallas  

d) Hygiea  

Explanation: Ceres has a tilted orbit.

100. Which planet has the most tilted axis among asteroids?  

a) Vesta ✅  

b) Ceres  

c) Pallas  

d) Hygiea  

Explanation: Vesta has a tilted axis.

101. The Sun is classified as which type of star?  

a) Red Giant  

b) Yellow Dwarf ✅  

c) White Dwarf  

d) Neutron Star  

Explanation: The Sun is a G-type main-sequence star (G2V), often called a yellow dwarf.

102. The Sun’s energy is produced by:  

a) Nuclear fission  

b) Nuclear fusion ✅  

c) Chemical reactions  

d) Radioactive decay  

Explanation: Fusion of hydrogen into helium in the core produces energy.

103. The Sun’s core temperature is approximately:  

a) 1 million °C  

b) 15 million °C ✅  

c) 100,000 °C  

d) 50 million °C  

Explanation: The Sun’s core reaches about 15 million °C.

104. The outermost layer of the Sun’s atmosphere is called:  

a) Photosphere  

b) Chromosphere  

c) Corona ✅  

d) Convective zone  

Explanation: The corona is the outermost layer, visible during eclipses.

105. The visible surface of the Sun is called:  

a) Photosphere ✅  

b) Chromosphere  

c) Corona  

d) Core  

Explanation: The photosphere is the Sun’s visible surface.

106. Sunspots appear darker because they are:  

a) Cooler ✅  

b) Hotter  

c) Brighter  

d) Larger  

Explanation: Sunspots are cooler regions on the photosphere.

107. The Sun completes one rotation approximately every:  

a) 10 days  

b) 27 days ✅  

c) 365 days  

d) 7 days  

Explanation: The Sun rotates once in about 27 days.

108. The solar wind is composed mainly of:  

a) Oxygen and nitrogen  

b) Hydrogen and helium ✅  

c) Carbon and iron  

d) Silicon and sulfur  

Explanation: Solar wind consists of charged particles, mainly protons and electrons.

109. The boundary between the Sun’s radiation and convection zones is called:  

a) Tachocline ✅  

b) Photosphere  

c) Corona  

d) Chromosphere  

Explanation: The tachocline separates the radiative and convective zones.

110. Solar flares are sudden releases of:  

a) Light only  

b) Magnetic energy ✅  

c) Heat only  

d) Sound waves  

Explanation: Solar flares are bursts of magnetic energy.

111. The Sun’s diameter is approximately:  

a) 1.4 million km ✅  

b) 500,000 km  

c) 2 million km  

d) 700,000 km  

Explanation: The Sun’s diameter is about 1.39 million km.

112. The Sun’s mass is about how many times Earth’s mass?  

a) 100,000  

b) 300,000 ✅  

c) 1,000,000  

d) 30,000  

Explanation: The Sun’s mass is ~333,000 times Earth’s.

113. The Sun’s energy reaches Earth in about:  

a) 1 second  

b) 8 minutes ✅  

c) 1 hour  

d) 24 hours  

Explanation: Light takes ~8 minutes to travel from Sun to Earth.

114. The Sun is located in which galaxy?  

a) Andromeda  

b) Milky Way ✅  

c) Triangulum  

d) Sombrero  

Explanation: The Sun is part of the Milky Way galaxy.

115. The Sun’s corona is hotter than the photosphere due to:  

a) Magnetic heating ✅  

b) Nuclear fusion  

c) Chemical reactions  

d) Gravity  

Explanation: Magnetic activity heats the corona.

116. Solar prominences are:  

a) Dark spots  

b) Large loops of plasma ✅  

c) Small eruptions  

d) Magnetic poles  

Explanation: Prominences are plasma loops extending from the Sun.

117. The Sun’s luminosity is approximately:  

a) 3.8 × 10²⁶ watts ✅  

b) 1 × 10²⁴ watts  

c) 5 × 10²⁸ watts  

d) 7 × 10²² watts  

Explanation: The Sun emits ~3.8 × 10²⁶ watts of energy.

118. The Sun’s magnetic cycle lasts about:  

a) 5 years  

b) 11 years ✅  

c) 20 years  

d) 50 years  

Explanation: The solar cycle is ~11 years long.

119. The Sun’s core is mainly composed of:  

a) Hydrogen ✅  

b) Helium  

c) Oxygen  

d) Carbon  

Explanation: Hydrogen makes up ~74% of the Sun’s mass.

120. The Sun’s corona extends millions of km into space and is visible during:  

a) Solar eclipse ✅  

b) Lunar eclipse  

c) Equinox  

d) Solstice  

Explanation: The corona is seen during total solar eclipses.

121. The Sun’s energy production process is called:  

a) Proton-proton chain ✅  

b) Carbon cycle  

c) Fission chain  

d) Neutron cycle  

Explanation: The Sun produces energy via the proton-proton chain reaction.

122. The Sun’s average surface temperature is:  

a) 15,000 °C  

b) 5,500 °C ✅  

c) 10,000 °C  

d) 20,000 °C  

Explanation: The photosphere averages ~5,500 °C.

123. Solar storms can disrupt:  

a) Earth’s magnetic field ✅  

b) Earth’s gravity  

c) Earth’s rotation  

d) Earth’s orbit  

Explanation: Solar storms affect Earth’s magnetosphere.

124. The Sun’s chromosphere lies:  

a) Above the photosphere ✅  

b) Below the core  

c) Inside the corona  

d) Between corona and core  

Explanation: The chromosphere is above the photosphere.

125. The Sun’s energy is transported outward by:  

a) Radiation and convection ✅  

b) Conduction only  

c) Magnetism only  

d) Gravity only  

Explanation: Energy moves via radiation and convection.

126. The Sun’s gravitational pull keeps planets:  

a) In orbit ✅  

b) Rotating  

c) Stationary  

d) Colliding  

Explanation: Gravity keeps planets orbiting the Sun.

127. The Sun’s age is approximately:  

a) 1 billion years  

b) 4.6 billion years ✅  

c) 10 billion years  

d) 500 million years  

Explanation: The Sun formed ~4.6 billion years ago.

128. The Sun’s future stage after main sequence will be:  

a) Red Giant ✅  

b) White Dwarf  

c) Neutron Star  

d) Black Hole  

Explanation: The Sun will expand into a red giant.

129. The Sun’s final stage will be:  

a) White Dwarf ✅  

b) Neutron Star  

c) Black Hole  

d) Supernova  

Explanation: The Sun will end as a white dwarf.

130. The Sun’s corona temperature is about:  

a) 1 million °C ✅  

b) 5,500 °C  

c) 15 million °C  

d) 100,000 °C  

Explanation: The corona reaches ~1 million °C.

131. The Sun’s rotation is faster at:  

a) Equator ✅  

b) Poles  

c) Core  

d) Corona  

Explanation: Differential rotation makes equator rotate faster.

132. The Sun’s magnetic field reverses every:  

a) 11 years  

b) 22 years ✅  

c) 33 years  

d) 44 years  

Explanation: Full magnetic cycle is ~22 years.

133. The Sun’s solar wind creates:  

a) Auroras ✅  

b) Earthquakes  

c) Volcanoes  

d) Tsunamis  

Explanation: Solar wind interacts with Earth’s magnetosphere to form auroras.

134. The Sun’s photosphere emits mostly:  

a) Visible light ✅  

b) Gamma rays  

c) X-rays  

d) Radio waves  

Explanation: The photosphere emits visible light.

135. The Sun’s corona is studied using:  

a) Coronagraph ✅  

b) Microscope  

c) Telescope only  

d) Spectrometer  

Explanation: Coronagraphs block the Sun’s disk to study corona.

136. The Sun’s energy output stabilizes due to:  

a) Hydrostatic equilibrium ✅  

b) Magnetic fields  

c) Gravity only  

d) Rotation  

Explanation: Balance between gravity and pressure stabilizes the Sun.

137. Solar eclipses occur when:  

a) Moon blocks Sun ✅  

b) Earth blocks Sun  

c) Sun blocks Moon  

d) Earth blocks Moon  

Explanation: The Moon passes between Earth and Sun.

138. The Sun’s nuclear fusion converts hydrogen into:  

a) Helium ✅  

b) Oxygen  

c) Carbon  

d) Nitrogen  

Explanation: Fusion produces helium from hydrogen.

139. The Sun’s solar cycle affects:  

a) Sunspot numbers ✅  

b) Earth’s orbit  

c) Earth’s rotation  

d) Earth’s gravity  

Explanation: Sunspot activity follows the solar cycle.

140. The Sun’s corona produces:  

a) Solar wind ✅  

b) Sunspots  

c) Prominences  

d) Photosphere  

Explanation: Solar wind originates in the corona.

141. The Sun’s chromosphere appears:  

a) Red ✅  

b) Blue  

c) Yellow  

d) White  

Explanation: The chromosphere looks reddish due to hydrogen emission lines.

142. The Sun’s corona is visible during:  

a) Total solar eclipse ✅  

b) Lunar eclipse  

c) Equinox  

d) Solstice  

Explanation: The corona can be seen when the Moon blocks the photosphere.

143. The Sun’s photosphere temperature is about:  

a) 5,500 °C ✅  

b) 15,000 °C  

c) 1,000 °C  

d) 20,000 °C  

Explanation: The photosphere averages ~5,500 °C.

144. The Sun’s core produces energy through:  

a) Proton-proton chain ✅  

b) Carbon cycle  

c) Fission  

d) Radioactive decay  

Explanation: Hydrogen nuclei fuse into helium via the proton-proton chain.

145. The Sun’s magnetic activity causes:  

a) Sunspots ✅  

b) Earthquakes  

c) Volcanoes  

d) Tsunamis  

Explanation: Sunspots are linked to magnetic field variations.

146. The Sun’s solar wind is responsible for:  

a) Auroras ✅  

b) Earth’s rotation  

c) Earthquakes  

d) Seasons  

Explanation: Solar wind interacts with Earth’s magnetosphere to produce auroras.

147. The Sun’s corona temperature is:  

a) 1 million °C ✅  

b) 5,500 °C  

c) 15 million °C  

d) 100,000 °C  

Explanation: The corona reaches ~1 million °C.

148. The Sun’s luminosity is approximately:  

a) 3.8 × 10²⁶ watts ✅  

b) 1 × 10²⁴ watts  

c) 5 × 10²⁸ watts  

d) 7 × 10²² watts  

Explanation: The Sun emits ~3.8 × 10²⁶ watts.

149. The Sun’s age is about:  

a) 4.6 billion years ✅  

b) 1 billion years  

c) 10 billion years  

d) 500 million years  

Explanation: The Sun formed ~4.6 billion years ago.

150. The Sun’s future stage after main sequence is:  

a) Red Giant ✅  

b) White Dwarf  

c) Neutron Star  

d) Black Hole  

Explanation: The Sun will expand into a red giant.

151. The Sun’s final stage will be:  

a) White Dwarf ✅  

b) Neutron Star  

c) Black Hole  

d) Supernova  

Explanation: The Sun will end as a white dwarf.

152. The Sun’s corona is studied using:  

a) Coronagraph ✅  

b) Microscope  

c) Telescope only  

d) Spectrometer  

Explanation: Coronagraphs block the Sun’s disk to study corona.

153. The Sun’s magnetic cycle lasts:  

a) 11 years ✅  

b) 5 years  

c) 20 years  

d) 50 years  

Explanation: The solar cycle is ~11 years long.

154. The Sun’s full magnetic reversal cycle is:  

a) 22 years ✅  

b) 11 years  

c) 33 years  

d) 44 years  

Explanation: Polarity reverses every 22 years.

155. The Sun’s gravitational pull keeps planets:  

a) In orbit ✅  

b) Rotating  

c) Stationary  

d) Colliding  

Explanation: Gravity keeps planets orbiting the Sun.

156. The Sun’s mass is about:  

a) 333,000 times Earth ✅  

b) 100,000 times Earth  

c) 1,000,000 times Earth  

d) 30,000 times Earth  

Explanation: The Sun’s mass is ~333,000 times Earth’s.

157. The Sun’s diameter is approximately:  

a) 1.4 million km ✅  

b) 500,000 km  

c) 2 million km  

d) 700,000 km  

Explanation: The Sun’s diameter is ~1.39 million km.

158. The Sun’s energy reaches Earth in:  

a) 8 minutes ✅  

b) 1 second  

c) 1 hour  

d) 24 hours  

Explanation: Light takes ~8 minutes to travel from Sun to Earth.

159. The Sun’s core is mainly composed of:  

a) Hydrogen ✅  

b) Helium  

c) Oxygen  

d) Carbon  

Explanation: Hydrogen makes up ~74% of the Sun’s mass.

160. The Sun’s surface activity includes:  

a) Sunspots ✅  

b) Earthquakes  

c) Volcanoes  

d) Tsunamis  

Explanation: Sunspots are surface magnetic phenomena.

161. The Sun’s prominences are:  

a) Plasma loops ✅  

b) Dark spots  

c) Magnetic poles  

d) Small eruptions  

Explanation: Prominences are plasma loops extending outward.

162. The Sun’s differential rotation means:  

a) Equator rotates faster ✅  

b) Poles rotate faster  

c) Core rotates faster  

d) Corona rotates faster  

Explanation: The equator rotates faster than the poles.

163. The Sun’s energy transport methods are:  

a) Radiation and convection ✅  

b) Conduction only  

c) Magnetism only  

d) Gravity only  

Explanation: Energy moves outward via radiation and convection.

164. The Sun’s hydrostatic equilibrium balances:  

a) Gravity and pressure ✅  

b) Magnetism and rotation  

c) Gravity and magnetism  

d) Rotation and pressure  

Explanation: Gravity inward is balanced by pressure outward.

165. The Sun’s solar storms can disrupt:  

a) Satellites ✅  

b) Earth’s orbit  

c) Earth’s rotation  

d) Earth’s gravity  

Explanation: Solar storms affect satellites and communications.

166. The Sun’s chromosphere lies:  

a) Above the photosphere ✅  

b) Below the core  

c) Inside the corona  

d) Between corona and core  

Explanation: The chromosphere is above the photosphere.

167. The Sun’s corona extends:  

a) Millions of km into space ✅  

b) Few hundred km  

c) Few thousand km  

d) Few meters  

Explanation: The corona stretches millions of km outward.

168. The Sun’s nuclear fusion converts:  

a) Hydrogen into helium ✅  

b) Oxygen into carbon  

c) Carbon into nitrogen  

d) Helium into hydrogen  

Explanation: Fusion produces helium from hydrogen.

169. The Sun’s solar cycle affects:  

a) Sunspot numbers ✅  

b) Earth’s orbit  

c) Earth’s rotation  

d) Earth’s gravity  

Explanation: Sunspot activity follows the solar cycle.

170. The Sun’s solar wind originates in:  

a) Corona ✅  

b) Photosphere  

c) Chromosphere  

d) Core  

Explanation: Solar wind is released from the corona.

171. The Sun’s photosphere emits primarily:  

a) Visible light ✅  

b) Gamma rays  

c) X-rays  

d) Radio waves  

Explanation: The photosphere is the source of visible light.

172. The Sun’s corona is hotter than the photosphere because of:  

a) Magnetic heating ✅  

b) Nuclear fusion  

c) Gravity  

d) Conduction  

Explanation: Magnetic activity heats the corona.

173. The Sun’s solar flares are caused by:  

a) Magnetic reconnection ✅  

b) Gravity  

c) Rotation  

d) Convection  

Explanation: Solar flares result from sudden magnetic energy release.

174. The Sun’s solar wind travels at speeds of:  

a) 400–800 km/s ✅  

b) 100 km/s  

c) 50 km/s  

d) 2000 km/s  

Explanation: Solar wind averages 400–800 km/s.

175. The Sun’s energy stabilizes due to:  

a) Hydrostatic equilibrium ✅  

b) Magnetism  

c) Rotation  

d) Gravity alone  

Explanation: Gravity inward balances pressure outward.

176. The Sun’s nuclear fusion occurs in:  

a) Core ✅  

b) Photosphere  

c) Corona  

d) Chromosphere  

Explanation: Fusion happens in the Sun’s core.

177. The Sun’s chromosphere is best observed in:  

a) Hydrogen-alpha light ✅  

b) X-rays  

c) Gamma rays  

d) Infrared  

Explanation: Hydrogen-alpha filters reveal the chromosphere.

178. The Sun’s corona produces:  

a) Solar wind ✅  

b) Sunspots  

c) Prominences  

d) Photosphere  

Explanation: Solar wind originates in the corona.

179. The Sun’s rotation period varies due to:  

a) Differential rotation ✅  

b) Uniform rotation  

c) Gravity  

d) Magnetism  

Explanation: Equator rotates faster than poles.

180. The Sun’s prominences are anchored in:  

a) Photosphere ✅  

b) Corona  

c) Chromosphere  

d) Core  

Explanation: Prominences extend from the photosphere.

181. The Sun’s magnetic field lines cause:  

a) Sunspots ✅  

b) Earthquakes  

c) Volcanoes  

d) Tsunamis  

Explanation: Sunspots form where magnetic fields emerge.

182. The Sun’s corona is studied during:  

a) Solar eclipses ✅  

b) Lunar eclipses  

c) Equinox  

d) Solstice  

Explanation: The corona is visible during total solar eclipses.

183. The Sun’s solar cycle influences:  

a) Satellite communication ✅  

b) Earth’s orbit  

c) Earth’s rotation  

d) Earth’s gravity  

Explanation: Solar activity affects satellites and radio signals.

184. The Sun’s energy output is measured as:  

a) Luminosity ✅  

b) Gravity  

c) Magnetism  

d) Rotation  

Explanation: Luminosity is the total energy emitted.

185. The Sun’s corona temperature is:  

a) ~1 million °C ✅  

b) 5,500 °C  

c) 15 million °C  

d) 100,000 °C  

Explanation: The corona reaches ~1 million °C.

186. The Sun’s photosphere thickness is about:  

a) 500 km ✅  

b) 5,000 km  

c) 50 km  

d) 10,000 km  

Explanation: The photosphere is ~500 km thick.

187. The Sun’s chromosphere thickness is about:  

a) 2,000 km ✅  

b) 200 km  

c) 20,000 km  

d) 50 km  

Explanation: The chromosphere is ~2,000 km thick.

188. The Sun’s corona extends:  

a) Millions of km ✅  

b) Hundreds of km  

c) Thousands of km  

d) Few meters  

Explanation: The corona stretches millions of km outward.

189. The Sun’s solar storms are also called:  

a) Coronal mass ejections ✅  

b) Earthquakes  

c) Volcanoes  

d) Tsunamis  

Explanation: CMEs are large solar eruptions.

190. The Sun’s energy source is:  

a) Nuclear fusion ✅  

b) Nuclear fission  

c) Chemical reactions  

d) Radioactive decay  

Explanation: Fusion of hydrogen into helium powers the Sun.

191. The Sun’s corona is hotter than the photosphere due to:  

a) Magnetic reconnection ✅  

b) Gravity  

c) Rotation  

d) Conduction  

Explanation: Magnetic reconnection heats the corona.

192. The Sun’s solar wind affects:  

a) Earth’s magnetosphere ✅  

b) Earth’s orbit  

c) Earth’s rotation  

d) Earth’s gravity  

Explanation: Solar wind disturbs Earth’s magnetic field.

193. The Sun’s energy output per second is:  

a) 3.8 × 10²⁶ joules ✅  

b) 1 × 10²⁴ joules  

c) 5 × 10²⁸ joules  

d) 7 × 10²² joules  

Explanation: The Sun emits ~3.8 × 10²⁶ joules per second.

194. The Sun’s nuclear fusion converts:  

a) Hydrogen into helium ✅  

b) Oxygen into carbon  

c) Carbon into nitrogen  

d) Helium into hydrogen  

Explanation: Fusion produces helium from hydrogen.

195. The Sun’s solar cycle lasts:  

a) 11 years ✅  

b) 5 years  

c) 20 years  

d) 50 years  

Explanation: The solar cycle is ~11 years long.

196. The Sun’s full magnetic cycle lasts:  

a) 22 years ✅  

b) 11 years  

c) 33 years  

d) 44 years  

Explanation: Polarity reverses every 22 years.

197. The Sun’s prominences are visible in:  

a) Hydrogen-alpha light ✅  

b) Gamma rays  

c) X-rays  

d) Infrared  

Explanation: Prominences are seen in hydrogen-alpha.

198. The Sun’s corona is hotter due to:  

a) Magnetic heating ✅  

b) Gravity  

c) Rotation  

d) Conduction  

Explanation: Magnetic activity heats the corona.

199. The Sun’s photosphere is the source of:  

a) Visible light ✅  

b) Gamma rays  

c) X-rays  

d) Radio waves  

Explanation: The photosphere emits visible light.

200. The Sun’s core temperature is about:  

a) 15 million °C ✅  

b) 5,500 °C  

c) 1 million °C  

d) 100,000 °C  

Explanation: The Sun’s core reaches ~15 million °C.

201. Mercury is the ______ planet from the Sun.  

a) First ✅  

b) Second  

c) Third  

d) Fourth  

Explanation: Mercury is the closest planet to the Sun.

202. Mercury’s orbital period around the Sun is:  

a) 365 days  

b) 88 days ✅  

c) 225 days  

d) 687 days  

Explanation: Mercury completes one orbit in 88 Earth days.

203. Mercury’s rotation period is:  

a) 24 hours  

b) 59 Earth days ✅  

c) 88 Earth days  

d) 243 Earth days  

Explanation: Mercury rotates once every 59 Earth days.

204. Mercury has ______ moons.  

a) 1  

b) 2  

c) None ✅  

d) 3  

Explanation: Mercury has no natural satellites.

205. Mercury’s atmosphere is:  

a) Thick CO₂  

b) Thin exosphere ✅  

c) Nitrogen-rich  

d) Oxygen-rich  

Explanation: Mercury has a very thin exosphere.

206. Mercury’s surface temperature ranges from:  

a) -173 °C to 427 °C ✅  

b) -50 °C to 100 °C  

c) -200 °C to 200 °C  

d) -100 °C to 300 °C  

Explanation: Mercury experiences extreme temperature variations.

207. Mercury’s diameter is approximately:  

a) 4,879 km ✅  

b) 6,371 km  

c) 12,742 km  

d) 3,500 km  

Explanation: Mercury’s diameter is ~4,879 km.

208. Mercury’s density is similar to:  

a) Earth ✅  

b) Jupiter  

c) Saturn  

d) Mars  

Explanation: Mercury is dense, like Earth, due to its large iron core.

209. Mercury’s surface is heavily:  

a) Cratered ✅  

b) Mountainous  

c) Covered in oceans  

d) Covered in forests  

Explanation: Mercury’s surface is covered with craters.

210. The largest impact basin on Mercury is:  

a) Caloris Basin ✅  

b) Hellas Basin  

c) South Pole–Aitken Basin  

d) Tycho Crater  

Explanation: Caloris Basin is Mercury’s largest impact crater.

211. Mercury’s axial tilt is:  

a) 23.5°  

b) 0.034° ✅  

c) 5°  

d) 10°  

Explanation: Mercury’s axis is almost upright.

212. Mercury’s orbit is highly:  

a) Circular  

b) Elliptical ✅  

c) Tilted  

d) Retrograde  

Explanation: Mercury has the most elliptical orbit of all planets.

213. Mercury’s escape velocity is:  

a) 4.25 km/s ✅  

b) 11.2 km/s  

c) 2 km/s  

d) 7 km/s  

Explanation: Mercury’s escape velocity is ~4.25 km/s.

214. Mercury’s magnetic field is:  

a) Strong like Jupiter  

b) Weak ✅  

c) Absent  

d) Same as Earth  

Explanation: Mercury has a weak magnetic field.

215. Mercury’s core is mostly:  

a) Iron ✅  

b) Nickel  

c) Silicate  

d) Carbon  

Explanation: Mercury has a large iron core.

216. Mercury’s albedo (reflectivity) is:  

a) 0.12 ✅  

b) 0.5  

c) 0.8  

d) 0.3  

Explanation: Mercury reflects only ~12% of sunlight.

217. Mercury’s orbit eccentricity is:  

a) 0.206 ✅  

b) 0.01  

c) 0.5  

d) 0.9  

Explanation: Mercury’s orbit is highly eccentric.

218. Mercury’s perihelion precession helped confirm:  

a) Newton’s laws  

b) Einstein’s General Relativity ✅  

c) Kepler’s laws  

d) Copernican theory  

Explanation: Mercury’s orbit shift confirmed relativity.

219. Mercury’s surface resembles:  

a) Moon ✅  

b) Earth  

c) Mars  

d) Venus  

Explanation: Mercury’s cratered surface resembles the Moon.

220. Mercury’s day-night cycle lasts:  

a) 176 Earth days ✅  

b) 59 Earth days  

c) 365 Earth days  

d) 88 Earth days  

Explanation: One Mercury day-night cycle equals 176 Earth days.

221. Mercury’s average distance from the Sun is:  

a) 57.9 million km ✅  

b) 149.6 million km  

c) 108.2 million km  

d) 227.9 million km  

Explanation: Mercury orbits at ~57.9 million km from the Sun.

222. Mercury’s gravity is:  

a) 3.7 m/s² ✅  

b) 9.8 m/s²  

c) 24.8 m/s²  

d) 1.6 m/s²  

Explanation: Mercury’s gravity is ~38% of Earth’s.

223. Mercury’s orbital inclination is:  

a) 7° ✅  

b) 23.5°  

c) 0°  

d) 15°  

Explanation: Mercury’s orbit is tilted ~7° to the ecliptic.

224. Mercury’s rotation is:  

a) Synchronous with orbit  

b) 3:2 resonance ✅  

c) Retrograde  

d) Same as Earth  

Explanation: Mercury rotates three times for every two orbits.

225. Mercury’s surface composition includes:  

a) Silicates ✅  

b) Water  

c) Methane  

d) Nitrogen  

Explanation: Mercury’s crust is mainly silicate rock.

226. Mercury’s polar regions contain:  

a) Water ice ✅  

b) Lava  

c) Carbon dioxide  

d) Methane  

Explanation: Water ice exists in permanently shadowed craters.

227. Mercury’s atmosphere is called:  

a) Exosphere ✅  

b) Troposphere  

c) Stratosphere  

d) Mesosphere  

Explanation: Mercury has a thin exosphere.

228. Mercury’s orbital speed is:  

a) 47.9 km/s ✅  

b) 30 km/s  

c) 24 km/s  

d) 12 km/s  

Explanation: Mercury moves fastest around the Sun.

229. Mercury’s surface pressure is:  

a) Near zero ✅  

b) 1 atm  

c) 0.5 atm  

d) 2 atm  

Explanation: Mercury has negligible atmospheric pressure.

230. Mercury’s surface features include:  

a) Scarps ✅  

b) Oceans  

c) Volcanoes  

d) Ice caps  

Explanation: Mercury has long cliffs called scarps.

231. Mercury’s orbital eccentricity causes:  

a) Temperature extremes ✅  

b) Uniform climate  

c) Thick atmosphere  

d) Stable seasons  

Explanation: Elliptical orbit leads to extreme temperatures.

232. Mercury’s rotation direction is:  

a) Prograde ✅  

b) Retrograde  

c) Tilted  

d) None  

Explanation: Mercury rotates in the same direction as its orbit.

233. Mercury’s orbital resonance is:  

a) 3:2 ✅  

b) 1:1  

c) 2:1  

d) 4:1  

Explanation: Mercury rotates three times for every two orbits.

234. Mercury’s surface resembles:  

a) Moon ✅  

b) Earth  

c) Mars  

d) Venus  

Explanation: Mercury’s cratered surface resembles the Moon.

235. Mercury’s perihelion distance is:  

a) 46 million km ✅  

b) 57.9 million km  

c) 108 million km  

d) 149.6 million km  

Explanation: Mercury’s closest distance to Sun is ~46 million km.

236. Mercury’s aphelion distance is:  

a) 69.8 million km ✅  

b) 57.9 million km  

c) 108 million km  

d) 149.6 million km  

Explanation: Mercury’s farthest distance from Sun is ~69.8 million km.

237. Mercury’s orbital period is:  

a) 88 days ✅  

b) 365 days  

c) 225 days  

d) 687 days  

Explanation: Mercury completes orbit in 88 Earth days.

238. Mercury’s rotation period is:  

a) 59 Earth days ✅  

b) 24 hours  

c) 243 Earth days  

d) 88 Earth days  

Explanation: Mercury rotates once every 59 Earth days.

239. Mercury’s orbital inclination is:  

a) 7° ✅  

b) 23.5°  

c) 0°  

d) 15°  

Explanation: Mercury’s orbit is tilted ~7°.

240. Mercury’s surface resembles:  

a) Moon ✅  

b) Earth  

c) Mars  

d) Venus  

Explanation: Mercury’s cratered surface resembles the Moon.

241. Venus is the ______ planet from the Sun.  

a) Second ✅  

b) First  

c) Third  

d) Fourth  

Explanation: Venus is the second planet from the Sun.

242. Venus is often called:  

a) Earth’s twin ✅  

b) Red Planet  

c) Gas Giant  

d) Ice Giant  

Explanation: Venus is similar in size and mass to Earth.

243. Venus’s orbital period around the Sun is:  

a) 365 days  

b) 225 days ✅  

c) 88 days  

d) 687 days  

Explanation: Venus completes one orbit in 225 Earth days.

244. Venus’s rotation period is:  

a) 24 hours  

b) 243 Earth days ✅  

c) 59 Earth days  

d) 365 Earth days  

Explanation: Venus rotates once every 243 Earth days.

245. Venus rotates in which direction?  

a) Retrograde ✅  

b) Prograde  

c) Tilted  

d) None  

Explanation: Venus rotates backward compared to most planets.

246. Venus’s axial tilt is:  

a) 23.5°  

b) 177° ✅  

c) 7°  

d) 0°  

Explanation: Venus’s axis is tilted ~177°, causing retrograde rotation.

247. Venus has ______ moons.  

a) 1  

b) 2  

c) None ✅  

d) 3  

Explanation: Venus has no natural satellites.

248. Venus’s atmosphere is mostly:  

a) Carbon dioxide ✅  

b) Oxygen  

c) Nitrogen  

d) Hydrogen  

Explanation: Venus’s atmosphere is ~96% CO₂.

249. Venus’s surface temperature is about:  

a) 465 °C ✅  

b) 100 °C  

c) 200 °C  

d) 600 °C  

Explanation: Venus is the hottest planet due to greenhouse effect.

250. Venus’s diameter is approximately:  

a) 12,104 km ✅  

b) 6,371 km  

c) 4,879 km  

d) 14,000 km  

Explanation: Venus’s diameter is ~12,104 km.

251. Venus’s gravity is:  

a) 8.87 m/s² ✅  

b) 9.8 m/s²  

c) 3.7 m/s²  

d) 24.8 m/s²  

Explanation: Venus’s gravity is ~90% of Earth’s.

252. Venus’s atmospheric pressure is:  

a) 92 times Earth ✅  

b) Same as Earth  

c) 10 times Earth  

d) 50 times Earth  

Explanation: Venus’s surface pressure is ~92 atm.

253. Venus’s clouds are composed of:  

a) Sulfuric acid ✅  

b) Water vapor  

c) Methane  

d) Carbon monoxide  

Explanation: Venus’s clouds contain sulfuric acid droplets.

254. Venus’s albedo (reflectivity) is:  

a) 0.65 ✅  

b) 0.12  

c) 0.3  

d) 0.8  

Explanation: Venus reflects ~65% of sunlight.

255. Venus’s escape velocity is:  

a) 10.36 km/s ✅  

b) 11.2 km/s  

c) 4.25 km/s  

d) 7 km/s  

Explanation: Venus’s escape velocity is ~10.36 km/s.

256. Venus’s average distance from the Sun is:  

a) 108.2 million km ✅  

b) 57.9 million km  

c) 149.6 million km  

d) 227.9 million km  

Explanation: Venus orbits at ~108.2 million km.

257. Venus’s surface is dominated by:  

a) Volcanoes ✅  

b) Oceans  

c) Craters  

d) Ice caps  

Explanation: Venus has many volcanic features.

258. Venus’s largest volcano is:  

a) Maat Mons ✅  

b) Olympus Mons  

c) Maxwell Montes  

d) Caloris Basin  

Explanation: Maat Mons is Venus’s tallest volcano.

259. Venus’s highest mountain is:  

a) Maxwell Montes ✅  

b) Maat Mons  

c) Olympus Mons  

d) Tycho Crater  

Explanation: Maxwell Montes is the highest peak on Venus.

260. Venus’s atmosphere causes:  

a) Runaway greenhouse effect ✅  

b) Stable climate  

c) Thin atmosphere  

d) Cold surface  

Explanation: Thick CO₂ traps heat, causing extreme temperatures.

261. Venus’s rotation is:  

a) Retrograde ✅  

b) Prograde  

c) Synchronous  

d) Same as Earth  

Explanation: Venus rotates backward compared to Earth.

262. Venus’s orbital eccentricity is:  

a) 0.007 ✅  

b) 0.206  

c) 0.5  

d) 0.01  

Explanation: Venus has nearly circular orbit.

263. Venus’s surface pressure is:  

a) 92 atm ✅  

b) 1 atm  

c) 10 atm  

d) 50 atm  

Explanation: Venus’s pressure is ~92 times Earth’s.

264. Venus’s clouds make it:  

a) Brightest planet ✅  

b) Darkest planet  

c) Coldest planet  

d) Smallest planet  

Explanation: Venus is highly reflective.

265. Venus’s day-night cycle lasts:  

a) 117 Earth days ✅  

b) 59 Earth days  

c) 243 Earth days  

d) 365 Earth days  

Explanation: One Venus day-night cycle equals 117 Earth days.

266. Venus’s magnetic field is:  

a) Very weak ✅  

b) Strong like Earth  

c) Absent  

d) Same as Jupiter  

Explanation: Venus has a weak magnetic field.

267. Venus’s surface features include:  

a) Plains and volcanoes ✅  

b) Oceans  

c) Ice caps  

d) Forests  

Explanation: Venus has volcanic plains.

268. Venus’s atmosphere contains traces of:  

a) Nitrogen ✅  

b) Oxygen  

c) Methane  

d) Hydrogen  

Explanation: Nitrogen makes up ~3.5% of Venus’s atmosphere.

269. Venus’s rotation period is longer than:  

a) Its year ✅  

b) Earth’s year  

c) Mars’s year  

d) Jupiter’s year  

Explanation: Venus rotates slower than it orbits.

270. Venus’s surface resembles:  

a) Volcanic plains ✅  

b) Oceans  

c) Cratered Moon  

d) Ice caps  

Explanation: Venus has volcanic plains.

271. Venus’s atmosphere is mainly:  

a) Carbon dioxide ✅  

b) Oxygen  

c) Nitrogen  

d) Hydrogen  

Explanation: CO₂ dominates Venus’s atmosphere.

272. Venus’s greenhouse effect makes it:  

a) Hottest planet ✅  

b) Coldest planet  

c) Smallest planet  

d) Brightest planet  

Explanation: Venus is the hottest planet.

273. Venus’s surface pressure is:  

a) 92 atm ✅  

b) 1 atm  

c) 10 atm  

d) 50 atm  

Explanation: Venus’s pressure is ~92 times Earth’s.

274. Venus’s escape velocity is:  

a) 10.36 km/s ✅  

b) 11.2 km/s  

c) 4.25 km/s  

d) 7 km/s  

Explanation: Venus’s escape velocity is ~10.36 km/s.

275. Venus’s albedo is:  

a) 0.65 ✅  

b) 0.12  

c) 0.3  

d) 0.8  

Explanation: Venus reflects ~65% of sunlight.

276. Venus’s average distance from the Sun is:  

a) 108.2 million km ✅  

b) 57.9 million km  

c) 149.6 million km  

d) 227.9 million km  

Explanation: Venus orbits at ~108.2 million km.

277. Venus’s diameter is:  

a) 12,104 km ✅  

b) 6,371 km  

c) 4,879 km  

d) 14,000 km  

Explanation: Venus’s diameter is ~12,104 km.

278. Venus’s gravity is:  

a) 8.87 m/s² ✅  

b) 9.8 m/s²  

c) 3.7 m/s²  

d) 24.8 m/s²  

Explanation: Venus’s gravity is ~90% of Earth’s.

279. Venus’s rotation direction is:  

a) Retrograde ✅  

b) Prograde  

c) Tilted  

d) None  

Explanation: Venus rotates backward compared to Earth.

280. Venus’s atmosphere is:  

a) Thick CO₂ ✅  

b) Thin exosphere  

c) Nitrogen-rich  

d) Oxygen-rich  

Explanation: Venus has a dense CO₂ atmosphere.

281. Earth is the ______ planet from the Sun.  

a) Third ✅  

b) Second  

c) Fourth  

d) Fifth  

Explanation: Earth is the third planet from the Sun.

282. Earth’s orbital period around the Sun is:  

a) 365 days ✅  

b) 225 days  

c) 88 days  

d) 687 days  

Explanation: Earth completes one orbit in 365 days.

283. Earth’s rotation period is:  

a) 24 hours ✅  

b) 59 days  

c) 243 days  

d) 10 hours  

Explanation: Earth rotates once every 24 hours.

284. Earth’s axial tilt is:  

a) 23.5° ✅  

b) 0°  

c) 7°  

d) 90°  

Explanation: Earth’s tilt causes seasons.

285. Earth’s diameter is approximately:  

a) 12,742 km ✅  

b) 6,371 km  

c) 4,879 km  

d) 14,000 km  

Explanation: Earth’s diameter is ~12,742 km.

286. Earth’s average distance from the Sun is:  

a) 149.6 million km ✅  

b) 57.9 million km  

c) 108.2 million km  

d) 227.9 million km  

Explanation: Earth orbits at ~149.6 million km.

287. Earth’s atmosphere is mostly:  

a) Nitrogen ✅  

b) Oxygen  

c) Carbon dioxide  

d) Hydrogen  

Explanation: Nitrogen makes up ~78% of Earth’s atmosphere.

288. Earth’s gravity is:  

a) 9.8 m/s² ✅  

b) 3.7 m/s²  

c) 24.8 m/s²  

d) 8.87 m/s²  

Explanation: Earth’s gravity is 9.8 m/s².

289. Earth’s escape velocity is:  

a) 11.2 km/s ✅  

b) 10.36 km/s  

c) 4.25 km/s  

d) 7 km/s  

Explanation: Earth’s escape velocity is ~11.2 km/s.

290. Earth’s albedo (reflectivity) is:  

a) 0.3 ✅  

b) 0.12  

c) 0.65  

d) 0.8  

Explanation: Earth reflects ~30% of sunlight.

291. Earth’s atmosphere contains about ______ oxygen.  

a) 21% ✅  

b) 50%  

c) 10%  

d) 78%  

Explanation: Oxygen makes up ~21% of Earth’s atmosphere.

292. Earth’s atmosphere contains about ______ nitrogen.  

a) 78% ✅  

b) 21%  

c) 50%  

d) 10%  

Explanation: Nitrogen dominates Earth’s atmosphere.

293. Earth’s average surface temperature is:  

a) 15 °C ✅  

b) 0 °C  

c) 50 °C  

d) -20 °C  

Explanation: Earth’s average temperature is ~15 °C.

294. Earth’s magnetic field protects against:  

a) Solar wind ✅  

b) Gravity  

c) Rotation  

d) Seasons  

Explanation: The magnetosphere shields Earth from solar wind.

295. Earth’s highest mountain is:  

a) Mount Everest ✅  

b) K2  

c) Kilimanjaro  

d) Denali  

Explanation: Mount Everest is the tallest mountain.

296. Earth’s deepest ocean trench is:  

a) Mariana Trench ✅  

b) Tonga Trench  

c) Puerto Rico Trench  

d) Java Trench  

Explanation: Mariana Trench is the deepest.

297. Earth’s largest ocean is:  

a) Pacific Ocean ✅  

b) Atlantic Ocean  

c) Indian Ocean  

d) Arctic Ocean  

Explanation: The Pacific is the largest ocean.

298. Earth’s largest continent is:  

a) Asia ✅  

b) Africa  

c) North America  

d) Europe  

Explanation: Asia is the largest continent.

299. Earth’s smallest continent is:  

a) Australia ✅  

b) Europe  

c) Antarctica  

d) South America  

Explanation: Australia is the smallest continent.

300. Earth’s rotation causes:  

a) Day and night ✅  

b) Seasons  

c) Gravity  

d) Magnetism  

Explanation: Rotation causes day-night cycle.

301. Earth’s revolution causes:  

a) Seasons ✅  

b) Day and night  

c) Gravity  

d) Magnetism  

Explanation: Revolution around the Sun causes seasons.

302. Earth’s atmosphere extends up to:  

a) 10,000 km ✅  

b) 1,000 km  

c) 100 km  

d) 500 km  

Explanation: The exosphere extends ~10,000 km.

303. Earth’s troposphere extends up to:  

a) 12 km ✅  

b) 50 km  

c) 80 km  

d) 100 km  

Explanation: Troposphere extends ~12 km.

304. Earth’s stratosphere extends up to:  

a) 50 km ✅  

b) 12 km  

c) 80 km  

d) 100 km  

Explanation: Stratosphere extends ~50 km.

305. Earth’s ozone layer is in:  

a) Stratosphere ✅  

b) Troposphere  

c) Mesosphere  

d) Thermosphere  

Explanation: Ozone layer lies in stratosphere.

306. Earth’s mesosphere extends up to:  

a) 80 km ✅  

b) 50 km  

c) 100 km  

d) 12 km  

Explanation: Mesosphere extends ~80 km.

307. Earth’s thermosphere extends up to:  

a) 600 km ✅  

b) 80 km  

c) 100 km  

d) 12 km  

Explanation: Thermosphere extends ~600 km.

308. Earth’s exosphere extends up to:  

a) 10,000 km ✅  

b) 1,000 km  

c) 100 km  

d) 500 km  

Explanation: Exosphere extends ~10,000 km.

309. Earth’s atmosphere is divided into:  

a) 5 layers ✅  

b) 3 layers  

c) 7 layers  

d) 2 layers  

Explanation: Atmosphere has 5 layers.

310. Earth’s hydrosphere covers:  

a) 71% ✅  

b) 50%  

c) 90%  

d) 30%  

Explanation: Water covers ~71% of Earth’s surface.

311. Earth’s biosphere supports:  

a) Life ✅  

b) Gravity  

c) Magnetism  

d) Rotation  

Explanation: Biosphere supports living organisms.

312. Earth’s lithosphere includes:  

a) Crust and upper mantle ✅  

b) Core only  

c) Atmosphere  

d) Oceans  

Explanation: Lithosphere is crust + upper mantle.

313. Earth’s mantle extends to:  

a) 2,900 km ✅  

b) 1,000 km  

c) 500 km  

d) 6,000 km  

Explanation: Mantle extends ~2,900 km.

314. Earth’s outer core is:  

a) Liquid ✅  

b) Solid  

c) Gas  

d) Plasma  

Explanation: Outer core is liquid iron and nickel.

315. Earth’s inner core is:  

a) Solid ✅  

b) Liquid  

c) Gas  

d) Plasma  

Explanation: Inner core is solid iron and nickel.

316. Earth’s crust thickness ranges from:  

a) 5–70 km ✅  

b) 100 km  

c) 200 km  

d) 10–20 km  

Explanation: Crust thickness varies from 5–70 km.

317. Earth’s magnetic field is generated by:  

a) Outer core ✅  

b) Inner core  

c) Mantle  

d) Crust  

Explanation: Liquid outer core generates magnetism.

318. Earth’s atmosphere pressure at sea level is:  

a) 1 atm ✅  

b) 10 atm  

c) 0.5 atm  

d) 2 atm  

Explanation: Sea level pressure is 1 atm.

319. Earth’s rotation direction is:  

a) Prograde ✅  

b) Retrograde  

c) Tilted  

d) None  

Explanation: Earth rotates eastward (prograde).

320. Earth’s revolution direction is:  

a) Counterclockwise ✅  

b) Clockwise  

c) Retrograde  

d) None  

Explanation: Earth revolves counterclockwise around the Sun.

321. Earth’s orbital eccentricity is:  

a) 0.0167 ✅  

b) 0.206  

c) 0.007  

d) 0.5  

Explanation: Earth’s orbit is nearly circular.

322. Earth’s perihelion distance is:  

a) 147 million km ✅  

b) 149.6 million km  

c) 108 million km  

d) 227.9 million km  

Explanation: Earth’s closest distance to Sun is ~147 million km.

323. Earth’s aphelion distance is:  

a) 152 million km ✅  

b) 149.6 million km  

c) 108 million km  

d) 227.9 million km  

Explanation: Earth’s farthest distance from Sun is ~152 million km.

324. Earth’s atmosphere contains trace gases like:  

a) Argon ✅  

b) Hydrogen  

c) Methane  

d) Helium  

Explanation: Argon makes up about 0.93% of Earth’s atmosphere.

325. Earth’s atmosphere contains trace greenhouse gases like:  

a) Carbon dioxide ✅  

b) Oxygen  

c) Nitrogen  

d) Argon  

Explanation: CO₂ is a key greenhouse gas in Earth’s atmosphere.

326. Earth’s atmosphere contains trace amounts of:  

a) Neon ✅  

b) Sodium  

c) Calcium  

d) Potassium  

Explanation: Neon is present in small amounts in Earth’s atmosphere.

327. Earth’s atmosphere contains trace amounts of:  

a) Helium ✅  

b) Lithium  

c) Magnesium  

d) Zinc  

Explanation: Helium is found in trace quantities in Earth’s atmosphere.

328. Earth’s atmosphere contains trace amounts of:  

a) Methane ✅  

b) Sulfur  

c) Iron  

d) Copper  

Explanation: Methane is a minor greenhouse gas in Earth’s atmosphere.

329. Earth’s atmosphere contains trace amounts of:  

a) Krypton ✅  

b) Lead  

c) Silver  

d) Gold  

Explanation: Krypton is present in very small amounts.

330. Earth’s atmosphere contains trace amounts of:  

a) Hydrogen ✅  

b) Sodium  

c) Calcium  

d) Potassium  

Explanation: Hydrogen exists in trace amounts in Earth’s atmosphere.

331. Earth’s atmosphere contains trace amounts of:  

a) Xenon ✅  

b) Nickel  

c) Tin  

d) Mercury  

Explanation: Xenon is a rare gas found in Earth’s atmosphere.

332. Earth’s atmosphere contains trace amounts of:  

a) Ozone ✅  

b) Nitrogen  

c) Oxygen  

d) Argon  

Explanation: Ozone is a trace gas in the stratosphere.

333. Earth’s atmosphere contains trace amounts of:  

a) Nitrous oxide ✅  

b) Carbon monoxide  

c) Hydrogen sulfide  

d) Ammonia  

Explanation: Nitrous oxide is a minor greenhouse gas.

334. Earth’s atmosphere contains trace amounts of:  

a) Carbon monoxide ✅  

b) Oxygen  

c) Nitrogen  

d) Argon  

Explanation: Carbon monoxide is present in small amounts.

335. Earth’s atmosphere contains trace amounts of:  

a) Water vapor ✅  

b) Hydrogen  

c) Neon  

d) Helium  

Explanation: Water vapor varies but is an important greenhouse gas.

336. Earth’s atmosphere contains trace amounts of:  

a) Sulfur dioxide ✅  

b) Nitrogen  

c) Oxygen  

d) Argon  

Explanation: Sulfur dioxide is present in trace amounts.

337. Earth’s atmosphere contains trace amounts of:  

a) Ammonia ✅  

b) Sodium  

c) Calcium  

d) Potassium  

Explanation: Ammonia is found in very small amounts.

338. Earth’s atmosphere contains trace amounts of:  

a) Hydrogen sulfide ✅  

b) Oxygen  

c) Nitrogen  

d) Argon  

Explanation: Hydrogen sulfide is present in trace quantities.

339. Earth’s atmosphere contains trace amounts of:  

a) Chlorofluorocarbons (CFCs) ✅  

b) Nitrogen  

c) Oxygen  

d) Argon  

Explanation: CFCs are man-made trace gases affecting ozone.

340. Earth’s atmosphere contains trace amounts of:  

a) Radon ✅  

b) Neon  

c) Helium  

d) Krypton  

Explanation: Radon is a radioactive trace gas.

341. Earth’s atmosphere contains trace amounts of:  

a) Hydrogen chloride ✅  

b) Nitrogen  

c) Oxygen  

d) Argon  

Explanation: Hydrogen chloride is present in trace amounts.

342. Earth’s atmosphere contains trace amounts of:  

a) Nitric oxide ✅  

b) Neon  

c) Helium  

d) Krypton  

Explanation: Nitric oxide is a trace gas.

343. Earth’s atmosphere contains trace amounts of:  

a) Hydrocarbons ✅  

b) Sodium  

c) Calcium  

d) Potassium  

Explanation: Hydrocarbons are present in small amounts.

344. Earth’s atmosphere contains trace amounts of:  

a) Volatile organic compounds (VOCs) ✅  

b) Nitrogen  

c) Oxygen  

d) Argon  

Explanation: VOCs are trace gases in Earth’s atmosphere.

345. Earth’s atmosphere contains trace amounts of:  

a) Hydrogen cyanide ✅  

b) Neon  

c) Helium  

d) Krypton  

Explanation: Hydrogen cyanide is found in very small amounts.

346. Earth’s atmosphere contains trace amounts of:  

a) Nitrogen dioxide ✅  

b) Oxygen  

c) Nitrogen  

d) Argon  

Explanation: Nitrogen dioxide is a trace pollutant gas.

347. Earth’s atmosphere contains trace amounts of:  

a) Carbonyl sulfide ✅  

b) Neon  

c) Helium  

d) Krypton  

Explanation: Carbonyl sulfide is a trace gas.

348. Earth’s atmosphere contains trace amounts of:  

a) Hydrogen peroxide ✅  

b) Oxygen  

c) Nitrogen  

d) Argon  

Explanation: Hydrogen peroxide is present in trace amounts.

349. Earth’s atmosphere contains trace amounts of:  

a) Peroxyacetyl nitrate (PAN) ✅  

b) Neon  

c) Helium  

d) Krypton  

Explanation: PAN is a trace pollutant gas.

350. Earth’s atmosphere contains trace amounts of:  

a) Chlorine ✅  

b) Nitrogen  

c) Oxygen  

d) Argon  

Explanation: Chlorine is present in trace amounts in Earth’s atmosphere.

351. Mars is the ______ planet from the Sun.  

a) Fourth ✅  

b) Third  

c) Fifth  

d) Sixth  

Explanation: Mars is the fourth planet from the Sun.

352. Mars is often called:  

a) Red Planet ✅  

b) Blue Planet  

c) Gas Giant  

d) Ice Giant  

Explanation: Mars appears red due to iron oxide on its surface.

353. Mars’s orbital period around the Sun is:  

a) 365 days  

b) 687 days ✅  

c) 225 days  

d) 88 days  

Explanation: Mars completes one orbit in 687 Earth days.

354. Mars’s rotation period is:  

a) 24 hours 37 minutes ✅  

b) 24 hours  

c) 59 days  

d) 10 hours  

Explanation: Mars rotates once in ~24.6 hours.

355. Mars’s axial tilt is:  

a) 23.5° ✅  

b) 0°  

c) 7°  

d) 90°  

Explanation: Mars’s tilt is similar to Earth’s, causing seasons.

356. Mars’s diameter is approximately:  

a) 6,792 km ✅  

b) 12,742 km  

c) 4,879 km  

d) 14,000 km  

Explanation: Mars’s diameter is ~6,792 km.

357. Mars’s average distance from the Sun is:  

a) 227.9 million km ✅  

b) 149.6 million km  

c) 108.2 million km  

d) 57.9 million km  

Explanation: Mars orbits at ~227.9 million km.

358. Mars’s gravity is:  

a) 3.7 m/s² ✅  

b) 9.8 m/s²  

c) 24.8 m/s²  

d) 8.87 m/s²  

Explanation: Mars’s gravity is ~38% of Earth’s.

359. Mars’s escape velocity is:  

a) 5.03 km/s ✅  

b) 11.2 km/s  

c) 4.25 km/s  

d) 7 km/s  

Explanation: Mars’s escape velocity is ~5.03 km/s.

360. Mars’s albedo (reflectivity) is:  

a) 0.25 ✅  

b) 0.12  

c) 0.65  

d) 0.3  

Explanation: Mars reflects ~25% of sunlight.

361. Mars has ______ moons.  

a) 2 ✅  

b) 1  

c) None  

d) 3  

Explanation: Mars has two moons, Phobos and Deimos.

362. Mars’s largest volcano is:  

a) Olympus Mons ✅  

b) Maat Mons  

c) Maxwell Montes  

d) Tycho Crater  

Explanation: Olympus Mons is the tallest volcano in the Solar System.

363. Mars’s largest canyon is:  

a) Valles Marineris ✅  

b) Grand Canyon  

c) Caloris Basin  

d) Hellas Basin  

Explanation: Valles Marineris is a massive canyon system.

364. Mars’s atmosphere is mostly:  

a) Carbon dioxide ✅  

b) Oxygen  

c) Nitrogen  

d) Hydrogen  

Explanation: Mars’s atmosphere is ~95% CO₂.

365. Mars’s average surface temperature is:  

a) -63 °C ✅  

b) 15 °C  

c) 0 °C  

d) 50 °C  

Explanation: Mars is cold, averaging -63 °C.

366. Mars’s polar caps are made of:  

a) Water ice and dry ice ✅  

b) Methane  

c) Ammonia  

d) Nitrogen  

Explanation: Polar caps contain water ice and frozen CO₂.

367. Mars’s atmosphere pressure is:  

a) 0.006 atm ✅  

b) 1 atm  

c) 0.5 atm  

d) 2 atm  

Explanation: Mars’s atmosphere is very thin.

368. Mars’s surface features include:  

a) Volcanoes and canyons ✅  

b) Oceans  

c) Forests  

d) Ice caps only  

Explanation: Mars has volcanoes, valleys, and craters.

369. Mars’s largest impact basin is:  

a) Hellas Basin ✅  

b) Caloris Basin  

c) South Pole–Aitken Basin  

d) Tycho Crater  

Explanation: Hellas Basin is a huge impact crater.

370. Mars’s rotation direction is:  

a) Prograde ✅  

b) Retrograde  

c) Tilted  

d) None  

Explanation: Mars rotates eastward like Earth.

371. Mars’s revolution direction is:  

a) Counterclockwise ✅  

b) Clockwise  

c) Retrograde  

d) None  

Explanation: Mars revolves counterclockwise around the Sun.

372. Mars’s orbital eccentricity is:  

a) 0.093 ✅  

b) 0.0167  

c) 0.007  

d) 0.206  

Explanation: Mars’s orbit is moderately elliptical.

373. Mars’s perihelion distance is:  

a) 206.7 million km ✅  

b) 149.6 million km  

c) 108.2 million km  

d) 227.9 million km  

Explanation: Mars’s closest distance to Sun is ~206.7 million km.

374. Mars’s aphelion distance is:  

a) 249.2 million km ✅  

b) 149.6 million km  

c) 108.2 million km  

d) 227.9 million km  

Explanation: Mars’s farthest distance from Sun is ~249.2 million km.

375. Mars’s atmosphere contains traces of:  

a) Nitrogen ✅  

b) Oxygen  

c) Methane  

d) Hydrogen  

Explanation: Nitrogen makes up ~2.7% of Mars’s atmosphere.

376. Mars’s atmosphere contains traces of:  

a) Argon ✅  

b) Neon  

c) Helium  

d) Krypton  

Explanation: Argon is ~1.6% of Mars’s atmosphere.

377. Mars’s atmosphere contains traces of:  

a) Oxygen ✅  

b) Nitrogen  

c) Methane  

d) Hydrogen  

Explanation: Oxygen is ~0.13% of Mars’s atmosphere.

378. Mars’s atmosphere contains traces of:  

a) Water vapor ✅  

b) Methane  

c) Hydrogen  

d) Neon  

Explanation: Water vapor exists in small amounts.

379. Mars’s atmosphere contains traces of:  

a) Methane ✅  

b) Nitrogen  

c) Oxygen  

d) Argon  

Explanation: Methane has been detected in trace amounts.

380. Mars’s surface resembles:  

a) Desert ✅  

b) Ocean  

c) Forest  

d) Ice cap  

Explanation: Mars’s surface is dry and desert-like.

381. Mars’s sky appears:  

a) Pinkish ✅  

b) Blue  

c) Green  

d) White  

Explanation: Dust makes Mars’s sky appear pink.

382. Mars’s dust storms can last:  

a) Weeks to months ✅  

b) Hours  

c) Days  

d) Years  

Explanation: Global dust storms can last for months.

383. Mars’s largest volcano height is:  

a) 21 km ✅  

b) 8 km  

c) 10 km  

d) 15 km  

Explanation: Olympus Mons is ~21 km tall.

384. Mars’s canyon system length is:  

a) 4,000 km ✅  

b) 500 km  

c) 1,000 km  

d) 2,000 km  

Explanation: Valles Marineris stretches ~4,000 km.

385. Mars’s moons are:  

a) Phobos and Deimos ✅  

b) Io and Europa  

c) Titan and Rhea  

d) Ganymede and Callisto  

Explanation: Mars has two small moons.

386. Mars’s moons are likely:  

a) Captured asteroids ✅  

b) Formed with Mars  

c) Volcanic fragments  

d) Ice chunks  

Explanation: Phobos and Deimos are thought to be captured asteroids.

387. Mars’s average density is:  

a) 3.93 g/cm³ ✅  

b) 5.51 g/cm³  

c) 1.33 g/cm³  

d) 0.7 g/cm³  

Explanation: Mars’s density is ~3.93 g/cm³.

388. Mars’s magnetic field is:  

a) Weak and patchy ✅  

b) Strong like Earth  

c) Absent  

d) Same as Jupiter  

Explanation: Mars has remnant crustal magnetism.

389. Mars’s seasons are caused by:  

a) Axial tilt ✅  

b) Rotation  

c) Gravity  

d) Orbit eccentricity  

Explanation: Tilt causes seasonal changes.

390. Mars’s year length is:  

a) 687 Earth days ✅  

b) 365 Earth days  

c) 225 Earth days  

d) 88 Earth days  

Explanation: Mars’s year is ~687 Earth days.

391. Mars’s day length is:  

a) 24 hours 37 minutes ✅  

b) 24 hours  

c) 59 days  

d) 10 hours  

Explanation: Mars’s day is ~24.6 hours.

392. Mars’s polar caps shrink and grow with:  

a) Seasons ✅  

b) Rotation  

c) Gravity  

d) Orbit eccentricity  

Explanation: Seasonal changes cause the polar caps to expand and contract.

393. Mars’s largest volcano is:  

a) Olympus Mons ✅  

b) Maat Mons  

c) Maxwell Montes  

d) Tycho Crater  

Explanation: Olympus Mons is the tallest volcano in the Solar System.

394. Mars’s canyon system is called:  

a) Valles Marineris ✅  

b) Grand Canyon  

c) Caloris Basin  

d) Hellas Basin  

Explanation: Valles Marineris is a massive canyon system on Mars.

395. Mars’s moons are:  

a) Phobos and Deimos ✅  

b) Io and Europa  

c) Titan and Rhea  

d) Ganymede and Callisto  

Explanation: Mars has two small moons, Phobos and Deimos.

396. Mars’s moons are thought to be:  

a) Captured asteroids ✅  

b) Formed with Mars  

c) Volcanic fragments  

d) Ice chunks  

Explanation: Phobos and Deimos are likely captured asteroids.

397. Mars’s average density is:  

a) 3.93 g/cm³ ✅  

b) 5.51 g/cm³  

c) 1.33 g/cm³  

d) 0.7 g/cm³  

Explanation: Mars’s density is ~3.93 g/cm³.

398. Mars’s magnetic field is:  

a) Weak and patchy ✅  

b) Strong like Earth  

c) Absent  

d) Same as Jupiter  

Explanation: Mars has remnant crustal magnetism.

399. Mars’s atmosphere pressure is:  

a) 0.006 atm ✅  

b) 1 atm  

c) 0.5 atm  

d) 2 atm  

Explanation: Mars’s atmosphere is very thin.

400. Mars’s atmosphere composition is mostly:  

a) Carbon dioxide ✅  

b) Oxygen  

c) Nitrogen  

d) Hydrogen  

Explanation: Mars’s atmosphere is ~95% CO₂.

401. Mars’s average surface temperature is:  

a) -63 °C ✅  

b) 15 °C  

c) 0 °C  

d) 50 °C  

Explanation: Mars is cold, averaging -63 °C.

402. Mars’s polar caps are made of:  

a) Water ice and dry ice ✅  

b) Methane  

c) Ammonia  

d) Nitrogen  

Explanation: Polar caps contain water ice and frozen CO₂.

403. Mars’s dust storms can last:  

a) Weeks to months ✅  

b) Hours  

c) Days  

d) Years  

Explanation: Global dust storms can last for months.

404. Mars’s sky appears:  

a) Pinkish ✅  

b) Blue  

c) Green  

d) White  

Explanation: Dust makes Mars’s sky appear pink.

405. Mars’s largest impact basin is:  

a) Hellas Basin ✅  

b) Caloris Basin  

c) South Pole–Aitken Basin  

d) Tycho Crater  

Explanation: Hellas Basin is a huge impact crater.

406. Mars’s canyon system length is:  

a) 4,000 km ✅  

b) 500 km  

c) 1,000 km  

d) 2,000 km  

Explanation: Valles Marineris stretches ~4,000 km.

407. Mars’s largest volcano height is:  

a) 21 km ✅  

b) 8 km  

c) 10 km  

d) 15 km  

Explanation: Olympus Mons is ~21 km tall.

408. Mars’s atmosphere contains traces of:  

a) Methane ✅  

b) Oxygen  

c) Nitrogen  

d) Argon  

Explanation: Methane has been detected in trace amounts.

409. Mars’s atmosphere contains traces of:  

a) Nitrogen ✅  

b) Oxygen  

c) Methane  

d) Hydrogen  

Explanation: Nitrogen makes up ~2.7% of Mars’s atmosphere.

410. Mars’s atmosphere contains traces of:  

a) Argon ✅  

b) Neon  

c) Helium  

d) Krypton  

Explanation: Argon is ~1.6% of Mars’s atmosphere.

411. Mars’s atmosphere contains traces of:  

a) Oxygen ✅  

b) Nitrogen  

c) Methane  

d) Hydrogen  

Explanation: Oxygen is ~0.13% of Mars’s atmosphere.

412. Mars’s atmosphere contains traces of:  

a) Water vapor ✅  

b) Methane  

c) Hydrogen  

d) Neon  

Explanation: Water vapor exists in small amounts.

413. Mars’s rotation period is:  

a) 24 hours 37 minutes ✅  

b) 24 hours  

c) 59 days  

d) 10 hours  

Explanation: Mars rotates once in ~24.6 hours.

414. Mars’s revolution period is:  

a) 687 Earth days ✅  

b) 365 Earth days  

c) 225 Earth days  

d) 88 Earth days  

Explanation: Mars completes one orbit in 687 Earth days.

415. Mars’s rotation direction is:  

a) Prograde ✅  

b) Retrograde  

c) Tilted  

d) None  

Explanation: Mars rotates eastward like Earth.

416. Mars’s revolution direction is:  

a) Counterclockwise ✅  

b) Clockwise  

c) Retrograde  

d) None  

Explanation: Mars revolves counterclockwise around the Sun.

417. Mars’s seasons are caused by:  

a) Axial tilt ✅  

b) Rotation  

c) Gravity  

d) Orbit eccentricity  

Explanation: Tilt causes seasonal changes.

418. Mars’s orbit eccentricity is:  

a) 0.093 ✅  

b) 0.0167  

c) 0.007  

d) 0.206  

Explanation: Mars’s orbit is moderately elliptical.

419. Mars’s perihelion distance is:  

a) 206.7 million km ✅  

b) 149.6 million km  

c) 108.2 million km  

d) 227.9 million km  

Explanation: Mars’s closest distance to Sun is ~206.7 million km.

420. Mars’s aphelion distance is:  

a) 249.2 million km ✅  

b) 149.6 million km  

c) 108.2 million km  

d) 227.9 million km  

Explanation: Mars’s farthest distance from Sun is ~249.2 million km.

421. Jupiter is the ______ planet from the Sun.  

a) Fifth ✅  

b) Fourth  

c) Sixth  

d) Seventh  

Explanation: Jupiter is the fifth planet from the Sun.

422. Jupiter is the ______ planet in the Solar System.  

a) Largest ✅  

b) Smallest  

c) Densest  

d) Coldest  

Explanation: Jupiter is the largest planet.

423. Jupiter’s diameter is approximately:  

a) 142,984 km ✅  

b) 12,742 km  

c) 49,000 km  

d) 100,000 km  

Explanation: Jupiter’s diameter is ~142,984 km.

424. Jupiter’s mass is about:  

a) 318 times Earth ✅  

b) 100 times Earth  

c) 500 times Earth  

d) 50 times Earth  

Explanation: Jupiter’s mass is ~318 Earths.

425. Jupiter’s gravity is:  

a) 24.8 m/s² ✅  

b) 9.8 m/s²  

c) 3.7 m/s²  

d) 8.87 m/s²  

Explanation: Jupiter’s gravity is ~2.5 times Earth’s.

426. Jupiter’s escape velocity is:  

a) 59.5 km/s ✅  

b) 11.2 km/s  

c) 5 km/s  

d) 20 km/s  

Explanation: Jupiter’s escape velocity is ~59.5 km/s.

427. Jupiter’s average distance from the Sun is:  

a) 778 million km ✅  

b) 149.6 million km  

c) 227.9 million km  

d) 108.2 million km  

Explanation: Jupiter orbits at ~778 million km.

428. Jupiter’s orbital period is:  

a) 11.9 years ✅  

b) 1 year  

c) 29 years  

d) 88 days  

Explanation: Jupiter completes one orbit in ~11.9 Earth years.

429. Jupiter’s rotation period is:  

a) 9 hours 56 minutes ✅  

b) 24 hours  

c) 10 hours 30 minutes  

d) 12 hours  

Explanation: Jupiter rotates once in ~10 hours.

430. Jupiter’s axial tilt is:  

a) 3.1° ✅  

b) 23.5°  

c) 25°  

d) 90°  

Explanation: Jupiter’s tilt is small, ~3.1°.

431. Jupiter’s atmosphere is mostly:  

a) Hydrogen and helium ✅  

b) Oxygen  

c) Nitrogen  

d) Carbon dioxide  

Explanation: Jupiter’s atmosphere is ~90% hydrogen, ~10% helium.

432. Jupiter’s Great Red Spot is:  

a) A giant storm ✅  

b) A volcano  

c) A crater  

d) A mountain  

Explanation: The Great Red Spot is a massive storm.

433. Jupiter’s average temperature is:  

a) -145 °C ✅  

b) 15 °C  

c) 0 °C  

d) 50 °C  

Explanation: Jupiter is very cold at the cloud tops.

434. Jupiter’s albedo (reflectivity) is:  

a) 0.52 ✅  

b) 0.3  

c) 0.12  

d) 0.65  

Explanation: Jupiter reflects ~52% of sunlight.

435. Jupiter has ______ moons.  

a) 95+ ✅  

b) 2  

c) 10  

d) 50  

Explanation: Jupiter has more than 95 confirmed moons.

436. Jupiter’s four largest moons are called:  

a) Galilean moons ✅  

b) Trojan moons  

c) Ring moons  

d) Dwarf moons  

Explanation: Io, Europa, Ganymede, and Callisto are Galilean moons.

437. Jupiter’s largest moon is:  

a) Ganymede ✅  

b) Callisto  

c) Io  

d) Europa  

Explanation: Ganymede is the largest moon in the Solar System.

438. Jupiter’s volcanic moon is:  

a) Io ✅  

b) Europa  

c) Ganymede  

d) Callisto  

Explanation: Io is volcanically active.

439. Jupiter’s icy moon with subsurface ocean is:  

a) Europa ✅  

b) Io  

c) Ganymede  

d) Callisto  

Explanation: Europa likely has a subsurface ocean.

440. Jupiter’s moon with oldest surface is:  

a) Callisto ✅  

b) Io  

c) Europa  

d) Ganymede  

Explanation: Callisto’s surface is heavily cratered.

441. Jupiter’s rings are:  

a) Faint ✅  

b) Bright  

c) Absent  

d) Thick  

Explanation: Jupiter has faint ring systems.

442. Jupiter’s magnetic field is:  

a) Strongest in Solar System ✅  

b) Weak  

c) Absent  

d) Same as Earth  

Explanation: Jupiter has the strongest magnetic field.

443. Jupiter’s magnetosphere extends:  

a) Millions of km ✅  

b) Hundreds of km  

c) Thousands of km  

d) Few meters  

Explanation: Jupiter’s magnetosphere is huge.

444. Jupiter’s atmosphere contains:  

a) Ammonia clouds ✅  

b) Oxygen clouds  

c) Nitrogen clouds  

d) Methane clouds  

Explanation: Ammonia forms cloud layers.

445. Jupiter’s atmosphere contains:  

a) Methane ✅  

b) Oxygen  

c) Nitrogen  

d) Carbon dioxide  

Explanation: Methane is present in small amounts.

446. Jupiter’s atmosphere contains:  

a) Water vapor ✅  

b) Oxygen  

c) Nitrogen  

d) Argon  

Explanation: Water vapor exists in Jupiter’s atmosphere.

447. Jupiter’s atmosphere contains:  

a) Hydrogen ✅  

b) Oxygen  

c) Nitrogen  

d) Carbon dioxide  

Explanation: Hydrogen dominates Jupiter’s atmosphere.

448. Jupiter’s atmosphere contains:  

a) Helium ✅  

b) Oxygen  

c) Nitrogen  

d) Carbon dioxide  

Explanation: Helium is ~10% of Jupiter’s atmosphere.

449. Jupiter’s atmosphere contains:  

a) Sulfur compounds ✅  

b) Oxygen  

c) Nitrogen  

d) Argon  

Explanation: Sulfur compounds are present in clouds.

450. Jupiter’s atmosphere contains:  

a) Phosphine ✅  

b) Oxygen  

c) Nitrogen  

d) Methane  

Explanation: Phosphine has been detected in Jupiter’s atmosphere.

451. Jupiter’s rotation causes:  

a) Strong bands ✅  

b) Weak winds  

c) No storms  

d) Stable climate  

Explanation: Rotation creates banded cloud patterns.

452. Jupiter’s storms include:  

a) Great Red Spot ✅  

b) Dust storms  

c) Volcanoes  

d) Hurricanes only  

Explanation: The Great Red Spot is a giant storm.

453. Jupiter’s magnetic field causes:  

a) Auroras ✅  

b) Earthquakes  

c) Volcanoes  

d) Tsunamis  

Explanation: Auroras occur near Jupiter’s poles.

454. Jupiter’s moons include:  

a) Io, Europa, Ganymede, Callisto ✅  

b) Titan, Rhea, Dione, Enceladus  

c) Triton, Nereid, Proteus, Larissa  

d) Phobos, Deimos  

Explanation: The Galilean moons are Jupiter’s largest.

455. Jupiter’s moon Ganymede is:  

a) Largest moon ✅  

b) Smallest moon  

c) Volcanic moon  

d) Icy moon  

Explanation: Ganymede is the largest moon.

456. Jupiter’s moon Io is:  

a) Volcanic moon ✅  

b) Icy moon  

c) Largest moon  

d) Cratered moon  

Explanation: Io is volcanically active.

457. Jupiter’s moon Europa is:  

a) Icy moon with ocean ✅  

b) Volcanic moon  

c) Largest moon  

d) Cratered moon  

Explanation: Europa likely has a subsurface ocean.

458. Jupiter’s moon Callisto is:  

a) Cratered moon ✅  

b) Volcanic moon  

c) Icy moon  

d) Largest moon  

Explanation: Callisto has an ancient, cratered surface.

459. Jupiter’s magnetic field is generated by:  

a) Metallic hydrogen ✅  

b) Iron core  

c) Silicate mantle  

d) Crust  

Explanation: Metallic hydrogen generates magnetism.

460. Jupiter’s interior includes:  

a) Metallic hydrogen ✅  

b) Solid iron  

c) Silicate mantle  

d) Crust only  

Explanation: Jupiter’s interior has metallic hydrogen.

461. Jupiter’s core is:  

a) Rocky/icy ✅  

b) Pure iron  

c) Absent  

d) Silicate mantle  

Explanation: Jupiter likely has a rocky/icy core.

462. Jupiter’s rotation period is:  

a) 9 hours 56 minutes ✅  

b) 24 hours  

c) 10 hours 30 minutes  

d) 12 hours  

Explanation: Jupiter rotates once in ~10 hours.

463. Jupiter’s orbital period is:  

a) 11.9 years ✅  

b) 1 year  

c) 29 years  

d) 88 days  

Explanation: Jupiter completes one orbit in ~11.9 Earth years.

464. Jupiter’s average temperature is:  

a) -145 °C ✅  

b) 15 °C  

c) 0 °C  

d) 50 °C  

Explanation: Jupiter’s cloud tops average -145 °C.

465. Jupiter’s orbital eccentricity is:  

a) 0.048 ✅  

b) 0.0167  

c) 0.093  

d) 0.206  

Explanation: Jupiter’s orbit is slightly elliptical.

466. Jupiter’s perihelion distance is:  

a) 740.5 million km ✅  

b) 778 million km  

c) 149.6 million km  

d) 227.9 million km  

Explanation: Jupiter’s closest distance to the Sun is ~740.5 million km.

467. Jupiter’s aphelion distance is:  

a) 816.6 million km ✅  

b) 778 million km  

c) 149.6 million km  

d) 227.9 million km  

Explanation: Jupiter’s farthest distance from the Sun is ~816.6 million km.

468. Jupiter’s rotation direction is:  

a) Prograde ✅  

b) Retrograde  

c) Tilted  

d) None  

Explanation: Jupiter rotates eastward like Earth.

469. Jupiter’s revolution direction is:  

a) Counterclockwise ✅  

b) Clockwise  

c) Retrograde  

d) None  

Explanation: Jupiter revolves counterclockwise around the Sun.

470. Jupiter’s magnetic field strength is:  

a) 20,000 times Earth ✅  

b) Same as Earth  

c) 100 times Earth  

d) 500 times Earth  

Explanation: Jupiter’s magnetic field is ~20,000 times stronger than Earth’s.

471. Jupiter’s auroras are caused by:  

a) Magnetic field interactions ✅  

b) Volcanoes  

c) Rotation  

d) Gravity  

Explanation: Auroras occur due to charged particles in Jupiter’s magnetosphere.

472. Jupiter’s rings are composed of:  

a) Dust particles ✅  

b) Ice chunks  

c) Large rocks  

d) Gas clouds  

Explanation: Jupiter’s rings are faint and made of dust.

473. Jupiter’s Great Red Spot has lasted for:  

a) Centuries ✅  

b) Days  

c) Years  

d) Decades  

Explanation: The Great Red Spot has been observed for hundreds of years.

474. Jupiter’s atmosphere layers include:  

a) Troposphere, stratosphere, thermosphere ✅  

b) Crust, mantle, core  

c) Lithosphere, hydrosphere, biosphere  

d) None  

Explanation: Jupiter’s atmosphere has layered structure.

475. Jupiter’s interior heat source is:  

a) Gravitational contraction ✅  

b) Nuclear fusion  

c) Chemical reactions  

d) Magnetism  

Explanation: Jupiter radiates heat from gravitational contraction.

476. Jupiter’s magnetic field is generated by:  

a) Metallic hydrogen ✅  

b) Iron core  

c) Silicate mantle  

d) Crust  

Explanation: Metallic hydrogen generates Jupiter’s magnetism.

477. Jupiter’s moons include:  

a) Io, Europa, Ganymede, Callisto ✅  

b) Titan, Rhea, Dione, Enceladus  

c) Triton, Nereid, Proteus, Larissa  

d) Phobos, Deimos  

Explanation: The Galilean moons are Jupiter’s largest.

478. Jupiter’s moon Io is:  

a) Volcanic moon ✅  

b) Icy moon  

c) Largest moon  

d) Cratered moon  

Explanation: Io is volcanically active.

479. Jupiter’s moon Europa is:  

a) Icy moon with ocean ✅  

b) Volcanic moon  

c) Largest moon  

d) Cratered moon  

Explanation: Europa likely has a subsurface ocean.

480. Jupiter’s moon Ganymede is:  

a) Largest moon ✅  

b) Smallest moon  

c) Volcanic moon  

d) Icy moon  

Explanation: Ganymede is the largest moon in the Solar System.

481. Jupiter’s moon Callisto is:  

a) Cratered moon ✅  

b) Volcanic moon  

c) Icy moon  

d) Largest moon  

Explanation: Callisto has an ancient, cratered surface.

482. Jupiter’s magnetosphere extends:  

a) Millions of km ✅  

b) Hundreds of km  

c) Thousands of km  

d) Few meters  

Explanation: Jupiter’s magnetosphere is enormous.

483. Jupiter’s atmosphere contains:  

a) Ammonia clouds ✅  

b) Oxygen clouds  

c) Nitrogen clouds  

d) Methane clouds  

Explanation: Ammonia forms cloud layers.

484. Jupiter’s atmosphere contains:  

a) Methane ✅  

b) Oxygen  

c) Nitrogen  

d) Carbon dioxide  

Explanation: Methane is present in small amounts.

485. Jupiter’s atmosphere contains:  

a) Water vapor ✅  

b) Oxygen  

c) Nitrogen  

d) Argon  

Explanation: Water vapor exists in Jupiter’s atmosphere.

486. Jupiter’s atmosphere contains:  

a) Hydrogen ✅  

b) Oxygen  

c) Nitrogen  

d) Carbon dioxide  

Explanation: Hydrogen dominates Jupiter’s atmosphere.

487. Jupiter’s atmosphere contains:  

a) Helium ✅  

b) Oxygen  

c) Nitrogen  

d) Carbon dioxide  

Explanation: Helium is ~10% of Jupiter’s atmosphere.

488. Jupiter’s atmosphere contains:  

a) Sulfur compounds ✅  

b) Oxygen  

c) Nitrogen  

d) Argon  

Explanation: Sulfur compounds are present in clouds.

489. Jupiter’s atmosphere contains:  

a) Phosphine ✅  

b) Oxygen  

c) Nitrogen  

d) Methane  

Explanation: Phosphine has been detected in Jupiter’s atmosphere.

490. Jupiter’s Great Red Spot is located in:  

a) Southern Hemisphere ✅  

b) Northern Hemisphere  

c) Equator  

d) Poles  

Explanation: The Great Red Spot lies in Jupiter’s southern hemisphere.

491. Saturn is the ______ planet from the Sun.  

a) Sixth ✅  

b) Fifth  

c) Seventh  

d) Fourth  

Explanation: Saturn is the sixth planet from the Sun.

492. Saturn is known as:  

a) Ringed Planet ✅  

b) Red Planet  

c) Blue Planet  

d) Gas Giant  

Explanation: Saturn is famous for its prominent rings.

493. Saturn’s diameter is approximately:  

a) 120,536 km ✅  

b) 142,984 km  

c) 12,742 km  

d) 49,000 km  

Explanation: Saturn’s diameter is ~120,536 km.

494. Saturn’s mass is about:  

a) 95 times Earth ✅  

b) 318 times Earth  

c) 50 times Earth  

d) 10 times Earth  

Explanation: Saturn’s mass is ~95 Earths.

495. Saturn’s gravity is:  

a) 10.44 m/s² ✅  

b) 9.8 m/s²  

c) 24.8 m/s²  

d) 3.7 m/s²  

Explanation: Saturn’s gravity is slightly stronger than Earth’s.

496. Saturn’s escape velocity is:  

a) 35.5 km/s ✅  

b) 59.5 km/s  

c) 11.2 km/s  

d) 5 km/s  

Explanation: Saturn’s escape velocity is ~35.5 km/s.

497. Saturn’s average distance from the Sun is:  

a) 1.43 billion km ✅  

b) 778 million km  

c) 227.9 million km  

d) 108.2 million km  

Explanation: Saturn orbits at ~1.43 billion km.

498. Saturn’s orbital period is:  

a) 29.5 years ✅  

b) 11.9 years  

c) 88 days  

d) 365 days  

Explanation: Saturn completes one orbit in ~29.5 Earth years.

499. Saturn’s rotation period is:  

a) 10 hours 33 minutes ✅  

b) 24 hours  

c) 12 hours  

d) 59 days  

Explanation: Saturn rotates once in ~10.5 hours.

500. Saturn’s axial tilt is:  

a) 26.7° ✅  

b) 23.5°  

c) 3.1°  

d) 90°  

Explanation: Saturn’s tilt is ~26.7°, causing seasons.

501. Saturn’s atmosphere is mostly:  

a) Hydrogen and helium ✅  

b) Oxygen  

c) Nitrogen  

d) Carbon dioxide  

Explanation: Saturn’s atmosphere is ~96% hydrogen, ~3% helium.

502. Saturn’s average temperature is:  

a) -178 °C ✅  

b) -145 °C  

c) 15 °C  

d) 0 °C  

Explanation: Saturn is very cold at the cloud tops.

503. Saturn’s albedo (reflectivity) is:  

a) 0.47 ✅  

b) 0.3  

c) 0.12  

d) 0.65  

Explanation: Saturn reflects ~47% of sunlight.

504. Saturn has ______ moons.  

a) 145+ ✅  

b) 95+  

c) 2  

d) 50  

Explanation: Saturn has more than 145 confirmed moons.

505. Saturn’s largest moon is:  

a) Titan ✅  

b) Rhea  

c) Iapetus  

d) Enceladus  

Explanation: Titan is Saturn’s largest moon.

506. Titan’s atmosphere is mostly:  

a) Nitrogen ✅  

b) Oxygen  

c) Carbon dioxide  

d) Hydrogen  

Explanation: Titan’s atmosphere is ~98% nitrogen.

507. Titan’s surface contains:  

a) Liquid methane and ethane ✅  

b) Water oceans  

c) Ice caps only  

d) Volcanoes  

Explanation: Titan has lakes of methane and ethane.

508. Saturn’s icy moon with geysers is:  

a) Enceladus ✅  

b) Titan  

c) Rhea  

d) Iapetus  

Explanation: Enceladus has geysers of water vapor.

509. Saturn’s moon with two-tone coloration is:  

a) Iapetus ✅  

b) Titan  

c) Rhea  

d) Enceladus  

Explanation: Iapetus has a dark and light hemisphere.

510. Saturn’s rings are composed of:  

a) Ice and rock ✅  

b) Dust only  

c) Gas clouds  

d) Volcanoes  

Explanation: Saturn’s rings are made of ice and rock particles.

511. Saturn’s rings extend up to:  

a) 282,000 km ✅  

b) 100,000 km  

c) 50,000 km  

d) 500,000 km  

Explanation: Rings extend ~282,000 km from Saturn.

512. Saturn’s rings are divided into:  

a) Seven main groups ✅  

b) Three groups  

c) Ten groups  

d) Two groups  

Explanation: Rings are divided into seven main groups.

513. Saturn’s magnetic field is:  

a) Strong ✅  

b) Weak  

c) Absent  

d) Same as Earth  

Explanation: Saturn has a strong magnetic field.

514. Saturn’s magnetosphere extends:  

a) Millions of km ✅  

b) Hundreds of km  

c) Thousands of km  

d) Few meters  

Explanation: Saturn’s magnetosphere is huge.

515. Saturn’s interior includes:  

a) Metallic hydrogen ✅  

b) Solid iron  

c) Silicate mantle  

d) Crust only  

Explanation: Saturn’s interior has metallic hydrogen.

516. Saturn’s core is:  

a) Rocky/icy ✅  

b) Pure iron  

c) Absent  

d) Silicate mantle  

Explanation: Saturn likely has a rocky/icy core.

517. Saturn’s rotation causes:  

a) Banding ✅  

b) Volcanoes  

c) Stable climate  

d) No storms  

Explanation: Saturn’s rotation creates banded cloud patterns.

518. Saturn’s atmosphere contains:  

a) Ammonia clouds ✅  

b) Oxygen clouds  

c) Nitrogen clouds  

d) Methane clouds  

Explanation: Ammonia forms cloud layers.

519. Saturn’s atmosphere contains:  

a) Methane ✅  

b) Oxygen  

c) Nitrogen  

d) Carbon dioxide  

Explanation: Methane is present in small amounts.

520. Saturn’s atmosphere contains:  

a) Water vapor ✅  

b) Oxygen  

c) Nitrogen  

d) Argon  

Explanation: Water vapor exists in Saturn’s atmosphere.

521. Saturn’s atmosphere contains:  

a) Hydrogen ✅  

b) Oxygen  

c) Nitrogen  

d) Carbon dioxide  

Explanation: Hydrogen dominates Saturn’s atmosphere.

522. Saturn’s atmosphere contains:  

a) Helium ✅  

b) Oxygen  

c) Nitrogen  

d) Carbon dioxide  

Explanation: Helium is ~3% of Saturn’s atmosphere.

523. Saturn’s atmosphere contains:  

a) Sulfur compounds ✅  

b) Oxygen  

c) Nitrogen  

d) Argon  

Explanation: Sulfur compounds are present in clouds.

524. Saturn’s atmosphere contains:  

a) Phosphine ✅  

b) Oxygen  

c) Nitrogen  

d) Methane  

Explanation: Phosphine has been detected in Saturn’s atmosphere.

525. Saturn’s rotation period is:  

a) 10 hours 33 minutes ✅  

b) 24 hours  

c) 12 hours  

d) 59 days  

Explanation: Saturn rotates once in ~10.5 hours.

526. Saturn’s orbital period is:  

a) 29.5 years ✅  

b) 11.9 years  

c) 88 days  

d) 365 days  

Explanation: Saturn completes one orbit in ~29.5 Earth years.

527. Saturn’s average temperature is:  

a) -178 °C ✅  

b) -145 °C  

c) 15 °C  

d) 0 °C  

Explanation: Saturn’s cloud tops average -178 °C.

528. Saturn’s orbital eccentricity is:  

a) 0.056 ✅  

b) 0.0167  

c) 0.093  

d) 0.206  

Explanation: Saturn’s orbit is slightly elliptical.

529. Saturn’s perihelion distance is:  

a) 1.35 billion km ✅  

b) 1.43 billion km  

c) 1.52 billion km  

d) 1.08 billion km  

Explanation: Saturn’s closest distance to Sun is ~1.35 billion km.

530. Saturn’s aphelion distance is:  

a) 1.51 billion km ✅  

b) 1.43 billion km  

c) 1.08 billion km  

d) 1.35 billion km  

Explanation: Saturn’s farthest distance from Sun is ~1.51 billion km.

531. Saturn’s rotation direction is:  

a) Prograde ✅  

b) Retrograde  

c) Tilted  

d) None  

Explanation: Saturn rotates eastward like Earth.

532. Saturn’s revolution direction is:  

a) Counterclockwise ✅  

b) Clockwise  

c) Retrograde  

d) None  

Explanation: Saturn revolves counterclockwise around the Sun.

533. Saturn’s rings are divided into:  

a) A, B, C rings ✅  

b) D, E, F rings  

c) G, H, I rings  

d) None  

Explanation: The main rings are A, B, and C, with additional faint rings.

534. Saturn’s rings are maintained by:  

a) Shepherd moons ✅  

b) Gravity only  

c) Magnetic fields  

d) Solar wind  

Explanation: Small moons help keep ring particles in place.

535. Saturn’s rings are mostly:  

a) Ice ✅  

b) Dust  

c) Gas  

d) Rock only  

Explanation: Rings are composed primarily of water ice.

536. Saturn’s rings thickness is:  

a) Less than 1 km ✅  

b) 10 km  

c) 100 km  

d) 1,000 km  

Explanation: Rings are very thin compared to their width.

537. Saturn’s rings are visible because of:  

a) Reflection of sunlight ✅  

b) Emission of light  

c) Magnetic fields  

d) Heat radiation  

Explanation: Rings reflect sunlight, making them visible.

538. Saturn’s largest moon is:  

a) Titan ✅  

b) Rhea  

c) Iapetus  

d) Enceladus  

Explanation: Titan is Saturn’s largest moon.

539. Titan’s atmosphere is:  

a) Thick ✅  

b) Thin  

c) Absent  

d) Same as Earth  

Explanation: Titan has a dense nitrogen-rich atmosphere.

540. Titan’s surface contains:  

a) Methane lakes ✅  

b) Water oceans  

c) Ice caps only  

d) Volcanoes  

Explanation: Titan has lakes of methane and ethane.

541. Enceladus is known for:  

a) Geysers ✅  

b) Volcanoes  

c) Craters  

d) Mountains  

Explanation: Enceladus ejects water vapor through geysers.

542. Iapetus is known for:  

a) Two-tone coloration ✅  

b) Volcanoes  

c) Atmosphere  

d) Oceans  

Explanation: Iapetus has a dark and light hemisphere.

543. Saturn’s magnetic field is:  

a) Strong ✅  

b) Weak  

c) Absent  

d) Same as Earth  

Explanation: Saturn has a strong magnetic field.

544. Saturn’s magnetosphere extends:  

a) Millions of km ✅  

b) Hundreds of km  

c) Thousands of km  

d) Few meters  

Explanation: Saturn’s magnetosphere is enormous.

545. Saturn’s interior includes:  

a) Metallic hydrogen ✅  

b) Solid iron  

c) Silicate mantle  

d) Crust only  

Explanation: Saturn’s interior has metallic hydrogen.

546. Saturn’s core is:  

a) Rocky/icy ✅  

b) Pure iron  

c) Absent  

d) Silicate mantle  

Explanation: Saturn likely has a rocky/icy core.

547. Saturn’s rotation causes:  

a) Banding ✅  

b) Volcanoes  

c) Stable climate  

d) No storms  

Explanation: Saturn’s rotation creates banded cloud patterns.

548. Saturn’s atmosphere contains:  

a) Ammonia clouds ✅  

b) Oxygen clouds  

c) Nitrogen clouds  

d) Methane clouds  

Explanation: Ammonia forms cloud layers.

549. Saturn’s atmosphere contains:  

a) Methane ✅  

b) Oxygen  

c) Nitrogen  

d) Carbon dioxide  

Explanation: Methane is present in small amounts.

550. Saturn’s atmosphere contains:  

a) Water vapor ✅  

b) Oxygen  

c) Nitrogen  

d) Argon  

Explanation: Water vapor exists in Saturn’s atmosphere.

551. Uranus is the ______ planet from the Sun.  

a) Seventh ✅  

b) Sixth  

c) Eighth  

d) Fifth  

Explanation: Uranus is the seventh planet from the Sun.

552. Uranus is classified as:  

a) Ice Giant ✅  

b) Gas Giant  

c) Terrestrial Planet  

d) Dwarf Planet  

Explanation: Uranus is an ice giant due to its composition.

553. Uranus’s diameter is approximately:  

a) 51,118 km ✅  

b) 12,742 km  

c) 120,536 km  

d) 142,984 km  

Explanation: Uranus’s diameter is ~51,118 km.

554. Uranus’s mass is about:  

a) 14.5 times Earth ✅  

b) 95 times Earth  

c) 318 times Earth  

d) 50 times Earth  

Explanation: Uranus’s mass is ~14.5 Earths.

555. Uranus’s gravity is:  

a) 8.69 m/s² ✅  

b) 9.8 m/s²  

c) 24.8 m/s²  

d) 3.7 m/s²  

Explanation: Uranus’s gravity is slightly less than Earth’s.

556. Uranus’s escape velocity is:  

a) 21.3 km/s ✅  

b) 11.2 km/s  

c) 35.5 km/s  

d) 59.5 km/s  

Explanation: Uranus’s escape velocity is ~21.3 km/s.

557. Uranus’s average distance from the Sun is:  

a) 2.87 billion km ✅  

b) 1.43 billion km  

c) 778 million km  

d) 4.5 billion km  

Explanation: Uranus orbits at ~2.87 billion km.

558. Uranus’s orbital period is:  

a) 84 years ✅  

b) 29.5 years  

c) 11.9 years  

d) 165 years  

Explanation: Uranus completes one orbit in ~84 Earth years.

559. Uranus’s rotation period is:  

a) 17 hours 14 minutes ✅  

b) 24 hours  

c) 10 hours  

d) 59 days  

Explanation: Uranus rotates once in ~17.2 hours.

560. Uranus’s axial tilt is:  

a) 98° ✅  

b) 23.5°  

c) 26.7°  

d) 3.1°  

Explanation: Uranus rotates almost on its side.

561. Uranus’s atmosphere is mostly:  

a) Hydrogen and helium ✅  

b) Oxygen  

c) Nitrogen  

d) Carbon dioxide  

Explanation: Uranus’s atmosphere is ~83% hydrogen, ~15% helium.

562. Uranus’s atmosphere contains:  

a) Methane ✅  

b) Oxygen  

c) Nitrogen  

d) Carbon dioxide  

Explanation: Methane gives Uranus its blue-green color.

563. Uranus’s average temperature is:  

a) -224 °C ✅  

b) -178 °C  

c) -145 °C  

d) 15 °C  

Explanation: Uranus is the coldest planet.

564. Uranus’s albedo (reflectivity) is:  

a) 0.51 ✅  

b) 0.3  

c) 0.12  

d) 0.65  

Explanation: Uranus reflects ~51% of sunlight.

565. Uranus has ______ moons.  

a) 27 ✅  

b) 2  

c) 50  

d) 95  

Explanation: Uranus has 27 known moons.

566. Uranus’s largest moon is:  

a) Titania ✅  

b) Oberon  

c) Ariel  

d) Miranda  

Explanation: Titania is Uranus’s largest moon.

567. Uranus’s moon with extreme cliffs is:  

a) Miranda ✅  

b) Titania  

c) Oberon  

d) Ariel  

Explanation: Miranda has giant cliffs and canyons.

568. Uranus’s moon with icy surface is:  

a) Ariel ✅  

b) Titania  

c) Oberon  

d) Miranda  

Explanation: Ariel has a bright icy surface.

569. Uranus’s moon Oberon is:  

a) Cratered ✅  

b) Volcanic  

c) Icy  

d) Smooth  

Explanation: Oberon has a heavily cratered surface.

570. Uranus’s rings are:  

a) Faint ✅  

b) Bright  

c) Absent  

d) Thick  

Explanation: Uranus has faint ring systems.

571. Uranus’s rings are composed of:  

a) Dark particles ✅  

b) Ice only  

c) Gas  

d) Dust only  

Explanation: Rings are made of dark material.

572. Uranus’s magnetic field is:  

a) Tilted ✅  

b) Strong like Jupiter  

c) Absent  

d) Same as Earth  

Explanation: Uranus’s magnetic field is tilted compared to its axis.

573. Uranus’s magnetosphere extends:  

a) Millions of km ✅  

b) Hundreds of km  

c) Thousands of km  

d) Few meters  

Explanation: Uranus’s magnetosphere is large.

574. Uranus’s interior includes:  

a) Icy mantle ✅  

b) Metallic hydrogen  

c) Solid iron  

d) Crust only  

Explanation: Uranus has an icy mantle.

575. Uranus’s core is:  

a) Rocky ✅  

b) Pure iron  

c) Absent  

d) Silicate mantle  

Explanation: Uranus likely has a rocky core.

576. Uranus’s rotation causes:  

a) Banding ✅  

b) Volcanoes  

c) Stable climate  

d) No storms  

Explanation: Uranus has faint banded cloud patterns.

577. Uranus’s atmosphere contains:  

a) Hydrogen ✅  

b) Oxygen  

c) Nitrogen  

d) Carbon dioxide  

Explanation: Hydrogen dominates Uranus’s atmosphere.

578. Uranus’s atmosphere contains:  

a) Helium ✅  

b) Oxygen  

c) Nitrogen  

d) Carbon dioxide  

Explanation: Helium is ~15% of Uranus’s atmosphere.

579. Uranus’s atmosphere contains:  

a) Methane ✅  

b) Oxygen  

c) Nitrogen  

d) Argon  

Explanation: Methane gives Uranus its color.

580. Uranus’s rotation direction is:  

a) Retrograde ✅  

b) Prograde  

c) Tilted  

d) None  

Explanation: Uranus rotates in retrograde motion.

581. Uranus’s revolution direction is:  

a) Counterclockwise ✅  

b) Clockwise  

c) Retrograde  

d) None  

Explanation: Uranus revolves counterclockwise around the Sun.

582. Uranus’s orbital eccentricity is:  

a) 0.046 ✅  

b) 0.0167  

c) 0.093  

d) 0.206  

Explanation: Uranus’s orbit is slightly elliptical.

583. Uranus’s perihelion distance is:  

a) 2.74 billion km ✅  

b) 2.87 billion km  

c) 1.43 billion km  

d) 4.5 billion km  

Explanation: Uranus’s closest distance to Sun is ~2.74 billion km.

584. Uranus’s aphelion distance is:  

a) 3.00 billion km ✅  

b) 2.87 billion km  

c) 1.43 billion km  

d) 4.5 billion km  

Explanation: Uranus’s farthest distance from Sun is ~3.00 billion km.

585. Uranus’s magnetic field is generated by:  

a) Icy mantle ✅  

b) Metallic hydrogen  

c) Iron core  

d) Crust  

Explanation: Uranus’s magnetic field comes from its icy mantle.

586. Uranus’s atmosphere contains:  

a) Water vapor ✅  

b) Oxygen  

c) Nitrogen  

d) Argon  

Explanation: Water vapor exists in Uranus’s atmosphere.

587. Uranus’s atmosphere contains:  

a) Ammonia ✅  

b) Oxygen  

c) Nitrogen  

d) Carbon dioxide  

Explanation: Ammonia is present in Uranus’s clouds.

588. Uranus’s atmosphere contains:  

a) Hydrogen sulfide ✅  

b) Oxygen  

c) Nitrogen  

d) Argon  

Explanation: Hydrogen sulfide has been detected in Uranus’s atmosphere.

589. Uranus’s average density is:  

a) 1.27 g/cm³ ✅  

b) 5.51 g/cm³  

c) 3.93 g/cm³  

d) 0.7 g/cm³  

Explanation: Uranus’s density is ~1.27 g/cm³.

590. Uranus’s magnetic field strength is:  

a) 50 times Earth ✅  

b) Same as Earth  

c) 100 times Earth  

d) 500 times Earth  

Explanation: Uranus’s magnetic field is ~50 times stronger than Earth’s.

591. Uranus’s auroras are caused by:  

a) Magnetic field interactions ✅  

b) Volcanoes  

c) Rotation  

d) Gravity  

Explanation: Auroras occur due to charged particles in Uranus’s magnetosphere.

592. Uranus’s rings are maintained by:  

a) Shepherd moons ✅  

b) Gravity only  

c) Magnetic fields  

d) Solar wind  

Explanation: Small moons help keep ring particles in place.

593. Uranus’s rings are mostly:  

a) Dark icy particles ✅  

b) Bright ice  

c) Gas clouds  

d) Dust only  

Explanation: Uranus’s rings are made of dark icy material.

594. Uranus’s rings are divided into:  

a) 13 distinct rings ✅  

b) 7 rings  

c) 3 rings  

d) 20 rings  

Explanation: Uranus has 13 known rings.

595. Uranus’s magnetic field is unusual because:  

a) It is tilted and offset ✅  

b) It is absent  

c) It is stronger than Jupiter’s  

d) It is aligned with axis  

Explanation: Uranus’s magnetic field is tilted and offset from its center.

596. Uranus’s magnetosphere produces:  

a) Auroras ✅  

b) Volcanoes  

c) Earthquakes  

d) Tsunamis  

Explanation: Charged particles in Uranus’s magnetosphere cause auroras.

597. Uranus’s interior heat is:  

a) Very low ✅  

b) Very high  

c) Same as Jupiter  

d) Same as Saturn  

Explanation: Uranus emits little internal heat compared to other giants.

598. Uranus’s average density is:  

a) 1.27 g/cm³ ✅  

b) 5.51 g/cm³  

c) 3.93 g/cm³  

d) 0.7 g/cm³  

Explanation: Uranus’s density is ~1.27 g/cm³.

599. Uranus’s atmosphere contains:  

a) Hydrogen sulfide ✅  

b) Oxygen  

c) Nitrogen  

d) Argon  

Explanation: Hydrogen sulfide has been detected in Uranus’s atmosphere.

600. Uranus’s color is due to:  

a) Methane absorption ✅  

b) Oxygen reflection  

c) Nitrogen scattering  

d) Hydrogen emission  

Explanation: Methane absorbs red light, giving Uranus a blue-green color.

601. Uranus’s rotation period is:  

a) 17 hours 14 minutes ✅  

b) 24 hours  

c) 10 hours  

d) 59 days  

Explanation: Uranus rotates once in ~17.2 hours.

602. Uranus’s orbital period is:  

a) 84 years ✅  

b) 29.5 years  

c) 11.9 years  

d) 165 years  

Explanation: Uranus completes one orbit in ~84 Earth years.

603. Uranus’s axial tilt is:  

a) 98° ✅  

b) 23.5°  

c) 26.7°  

d) 3.1°  

Explanation: Uranus rotates almost on its side.

604. Uranus’s revolution direction is:  

a) Counterclockwise ✅  

b) Clockwise  

c) Retrograde  

d) None  

Explanation: Uranus revolves counterclockwise around the Sun.

605. Uranus’s rotation direction is:  

a) Retrograde ✅  

b) Prograde  

c) Tilted  

d) None  

Explanation: Uranus rotates in retrograde motion.

606. Uranus’s perihelion distance is:  

a) 2.74 billion km ✅  

b) 2.87 billion km  

c) 1.43 billion km  

d) 3.00 billion km  

Explanation: Uranus’s closest distance to Sun is ~2.74 billion km.

607. Uranus’s aphelion distance is:  

a) 3.00 billion km ✅  

b) 2.87 billion km  

c) 1.43 billion km  

d) 2.74 billion km  

Explanation: Uranus’s farthest distance from Sun is ~3.00 billion km.

608. Uranus’s orbital eccentricity is:  

a) 0.046 ✅  

b) 0.0167  

c) 0.093  

d) 0.206  

Explanation: Uranus’s orbit is slightly elliptical.

609. Uranus’s magnetic field strength is:  

a) 50 times Earth ✅  

b) Same as Earth  

c) 100 times Earth  

d) 500 times Earth  

Explanation: Uranus’s magnetic field is ~50 times stronger than Earth’s.

610. Uranus’s magnetosphere extends:  

a) Millions of km ✅  

b) Hundreds of km  

c) Thousands of km  

d) Few meters  

Explanation: Uranus’s magnetosphere is enormous.

611. Neptune is the ______ planet from the Sun.  

a) Eighth ✅  

b) Seventh  

c) Ninth  

d) Sixth  

Explanation: Neptune is the eighth planet from the Sun.

612. Neptune is classified as:  

a) Ice Giant ✅  

b) Gas Giant  

c) Terrestrial Planet  

d) Dwarf Planet  

Explanation: Neptune is an ice giant due to its composition.

613. Neptune’s diameter is approximately:  

a) 49,528 km ✅  

b) 51,118 km  

c) 12,742 km  

d) 120,536 km  

Explanation: Neptune’s diameter is ~49,528 km.

614. Neptune’s mass is about:  

a) 17 times Earth ✅  

b) 14.5 times Earth  

c) 95 times Earth  

d) 318 times Earth  

Explanation: Neptune’s mass is ~17 Earths.

615. Neptune’s gravity is:  

a) 11.15 m/s² ✅  

b) 9.8 m/s²  

c) 24.8 m/s²  

d) 3.7 m/s²  

Explanation: Neptune’s gravity is slightly stronger than Earth’s.

616. Neptune’s escape velocity is:  

a) 23.5 km/s ✅  

b) 21.3 km/s  

c) 35.5 km/s  

d) 59.5 km/s  

Explanation: Neptune’s escape velocity is ~23.5 km/s.

617. Neptune’s average distance from the Sun is:  

a) 4.5 billion km ✅  

b) 2.87 billion km  

c) 1.43 billion km  

d) 778 million km  

Explanation: Neptune orbits at ~4.5 billion km.

618. Neptune’s orbital period is:  

a) 165 years ✅  

b) 84 years  

c) 29.5 years  

d) 11.9 years  

Explanation: Neptune completes one orbit in ~165 Earth years.

619. Neptune’s rotation period is:  

a) 16 hours 6 minutes ✅  

b) 17 hours 14 minutes  

c) 10 hours  

d) 24 hours  

Explanation: Neptune rotates once in ~16 hours.

620. Neptune’s axial tilt is:  

a) 28.3° ✅  

b) 23.5°  

c) 98°  

d) 3.1°  

Explanation: Neptune’s tilt is ~28.3°, causing seasons.

621. Neptune’s atmosphere is mostly:  

a) Hydrogen and helium ✅  

b) Oxygen  

c) Nitrogen  

d) Carbon dioxide  

Explanation: Neptune’s atmosphere is ~80% hydrogen, ~19% helium.

622. Neptune’s atmosphere contains:  

a) Methane ✅  

b) Oxygen  

c) Nitrogen  

d) Carbon dioxide  

Explanation: Methane gives Neptune its blue color.

623. Neptune’s average temperature is:  

a) -214 °C ✅  

b) -178 °C  

c) -145 °C  

d) 15 °C  

Explanation: Neptune is very cold at the cloud tops.

624. Neptune’s albedo (reflectivity) is:  

a) 0.41 ✅  

b) 0.3  

c) 0.12  

d) 0.65  

Explanation: Neptune reflects ~41% of sunlight.

625. Neptune has ______ moons.  

a) 14 ✅  

b) 27  

c) 50  

d) 95  

Explanation: Neptune has 14 known moons.

626. Neptune’s largest moon is:  

a) Triton ✅  

b) Nereid  

c) Proteus  

d) Larissa  

Explanation: Triton is Neptune’s largest moon.

627. Triton’s orbit is:  

a) Retrograde ✅  

b) Prograde  

c) Circular  

d) Tilted  

Explanation: Triton orbits Neptune in retrograde motion.

628. Triton’s surface contains:  

a) Nitrogen ice ✅  

b) Methane lakes  

c) Water oceans  

d) Volcanoes  

Explanation: Triton’s surface is covered with nitrogen ice.

629. Triton has:  

a) Cryovolcanoes ✅  

b) Lava volcanoes  

c) Mountains only  

d) Atmosphere only  

Explanation: Triton has cryovolcanic activity.

630. Neptune’s rings are:  

a) Faint ✅  

b) Bright  

c) Absent  

d) Thick  

Explanation: Neptune has faint ring systems.

631. Neptune’s rings are composed of:  

a) Dark particles ✅  

b) Ice only  

c) Gas  

d) Dust only  

Explanation: Rings are made of dark material.

632. Neptune’s magnetic field is:  

a) Tilted and offset ✅  

b) Strong like Jupiter  

c) Absent  

d) Same as Earth  

Explanation: Neptune’s magnetic field is tilted and offset.

633. Neptune’s magnetosphere extends:  

a) Millions of km ✅  

b) Hundreds of km  

c) Thousands of km  

d) Few meters  

Explanation: Neptune’s magnetosphere is large.

634. Neptune’s interior includes:  

a) Icy mantle ✅  

b) Metallic hydrogen  

c) Solid iron  

d) Crust only  

Explanation: Neptune has an icy mantle.

635. Neptune’s core is:  

a) Rocky ✅  

b) Pure iron  

c) Absent  

d) Silicate mantle  

Explanation: Neptune likely has a rocky core.

636. Neptune’s rotation causes:  

a) Banding ✅  

b) Volcanoes  

c) Stable climate  

d) No storms  

Explanation: Neptune has faint banded cloud patterns.

637. Neptune’s atmosphere contains:  

a) Hydrogen ✅  

b) Oxygen  

c) Nitrogen  

d) Carbon dioxide  

Explanation: Hydrogen dominates Neptune’s atmosphere.

638. Neptune’s atmosphere contains:  

a) Helium ✅  

b) Oxygen  

c) Nitrogen  

d) Carbon dioxide  

Explanation: Helium is ~19% of Neptune’s atmosphere.

639. Neptune’s atmosphere contains:  

a) Methane ✅  

b) Oxygen  

c) Nitrogen  

d) Argon  

Explanation: Methane gives Neptune its color.

640. Neptune’s strongest storm is called:  

a) Great Dark Spot ✅  

b) Great Red Spot  

c) White Oval  

d) Polar Vortex  

Explanation: The Great Dark Spot is a massive storm.

641. Neptune’s winds reach speeds of:  

a) 2,100 km/h ✅  

b) 500 km/h  

c) 1,000 km/h  

d) 3,000 km/h  

Explanation: Neptune has the fastest winds in the Solar System.

642. Neptune’s magnetic field strength is:  

a) 27 times Earth ✅  

b) Same as Earth  

c) 50 times Earth  

d) 500 times Earth  

Explanation: Neptune’s magnetic field is ~27 times stronger than Earth’s.

643. Neptune’s auroras are caused by:  

a) Magnetic field interactions ✅  

b) Volcanoes  

c) Rotation  

d) Gravity  

Explanation: Auroras occur due to charged particles in Neptune’s magnetosphere.

644. Neptune’s rings are maintained by:  

a) Shepherd moons ✅  

b) Gravity only  

c) Magnetic fields  

d) Solar wind  

Explanation: Small moons help keep ring particles in place.

645. Neptune’s average density is:  

a) 1.64 g/cm³ ✅  

b) 5.51 g/cm³  

c) 3.93 g/cm³  

d) 0.7 g/cm³  

Explanation: Neptune’s density is ~1.64 g/cm³.

646. Neptune’s interior heat is:  

a) High ✅  

b) Low  

c) Same as Uranus  

d) Absent  

Explanation: Neptune emits more heat than it receives from the Sun.

647. Neptune’s perihelion distance is:  

a) 4.45 billion km ✅  

b) 4.5 billion km  

c) 2.87 billion km  

d) 1.43 billion km  

Explanation: Neptune’s closest distance to Sun is ~4.45 billion km.

648. Neptune’s aphelion distance is:  

a) 4.55 billion km ✅  

b) 4.5 billion km  

c) 2.87 billion km  

d) 1.43 billion km  

Explanation: Neptune’s farthest distance from Sun is ~4.55 billion km.

649. Neptune’s orbital eccentricity is:  

a) 0.009 ✅  

b) 0.046  

c) 0.093  

d) 0.206  

Explanation: Neptune’s orbit is nearly circular.

650. Neptune’s rotation direction is:  

a) Prograde ✅  

b) Retrograde  

c) Tilted  

d) None  

Explanation: Neptune rotates eastward like Earth.

651. Neptune’s revolution direction is:  

a) Counterclockwise ✅  

b) Clockwise  

c) Retrograde  

d) None  

Explanation: Neptune revolves counterclockwise around the Sun.

652. Neptune’s magnetic field is generated by:  

a) Icy mantle ✅  

b) Metallic hydrogen  

c) Iron core  

d) Crust  

Explanation: Neptune’s magnetic field comes from its icy mantle.

653. Neptune’s atmosphere contains:  

a) Water vapor ✅  

b) Oxygen  

c) Nitrogen  

d) Argon  

Explanation: Water vapor exists in Neptune’s atmosphere.

654. Neptune’s atmosphere contains:  

a) Ammonia ✅  

b) Oxygen  

c) Nitrogen  

d) Carbon dioxide  

Explanation: Ammonia is present in Neptune’s clouds.

655. Neptune’s atmosphere contains:  

a) Hydrogen sulfide ✅  

b) Oxygen  

c) Nitrogen  

d) Argon  

Explanation: Hydrogen sulfide has been detected in Neptune’s atmosphere.

656. Neptune’s average density is:  

a) 1.64 g/cm³ ✅  

b) 5.51 g/cm³  

c) 3.93 g/cm³  

d) 0.7 g/cm³  

Explanation: Neptune’s density is ~1.64 g/cm³.

657. Neptune’s interior heat is:  

a) High ✅  

b) Low  

c) Same as Uranus  

d) Absent  

Explanation: Neptune emits more heat than it receives from the Sun.

658. Neptune’s strongest storm is:  

a) Great Dark Spot ✅  

b) Great Red Spot  

c) White Oval  

d) Polar Vortex  

Explanation: The Great Dark Spot is a massive storm on Neptune.

659. Neptune’s winds reach speeds of:  

a) 2,100 km/h ✅  

b) 500 km/h  

c) 1,000 km/h  

d) 3,000 km/h  

Explanation: Neptune has the fastest winds in the Solar System.

660. Neptune’s magnetic field is:  

a) Tilted and offset ✅  

b) Strong like Jupiter  

c) Absent  

d) Same as Earth  

Explanation: Neptune’s magnetic field is tilted and offset from its axis.

661. Neptune’s magnetic field strength is:  

a) 27 times Earth ✅  

b) Same as Earth  

c) 50 times Earth  

d) 500 times Earth  

Explanation: Neptune’s magnetic field is ~27 times stronger than Earth’s.

662. Neptune’s auroras are caused by:  

a) Magnetic field interactions ✅  

b) Volcanoes  

c) Rotation  

d) Gravity  

Explanation: Auroras occur due to charged particles in Neptune’s magnetosphere.

663. Neptune’s rings are maintained by:  

a) Shepherd moons ✅  

b) Gravity only  

c) Magnetic fields  

d) Solar wind  

Explanation: Small moons help keep ring particles in place.

664. Neptune’s perihelion distance is:  

a) 4.45 billion km ✅  

b) 4.5 billion km  

c) 2.87 billion km  

d) 1.43 billion km  

Explanation: Neptune’s closest distance to Sun is ~4.45 billion km.

665. Neptune’s aphelion distance is:  

a) 4.55 billion km ✅  

b) 4.5 billion km  

c) 2.87 billion km  

d) 1.43 billion km  

Explanation: Neptune’s farthest distance from Sun is ~4.55 billion km.

666. Neptune’s orbital eccentricity is:  

a) 0.009 ✅  

b) 0.046  

c) 0.093  

d) 0.206  

Explanation: Neptune’s orbit is nearly circular.

667. Neptune’s rotation direction is:  

a) Prograde ✅  

b) Retrograde  

c) Tilted  

d) None  

Explanation: Neptune rotates eastward like Earth.

668. Neptune’s revolution direction is:  

a) Counterclockwise ✅  

b) Clockwise  

c) Retrograde  

d) None  

Explanation: Neptune revolves counterclockwise around the Sun.

669. Neptune’s magnetic field is generated by:  

a) Icy mantle ✅  

b) Metallic hydrogen  

c) Iron core  

d) Crust  

Explanation: Neptune’s magnetic field comes from its icy mantle.

670. Neptune’s magnetosphere extends:  

a) Millions of km ✅  

b) Hundreds of km  

c) Thousands of km  

d) Few meters  

Explanation: Neptune’s magnetosphere is enormous.

671. Pluto is classified as:  

a) Dwarf planet ✅  

b) Terrestrial planet  

c) Gas giant  

d) Ice giant  

Explanation: Pluto was reclassified as a dwarf planet in 2006.

672. Pluto is the ______ largest dwarf planet.  

a) Second ✅  

b) First  

c) Third  

d) Fourth  

Explanation: Pluto is the second largest dwarf planet after Eris.

673. Pluto’s diameter is approximately:  

a) 2,377 km ✅  

b) 12,742 km  

c) 6,792 km  

d) 4,879 km  

Explanation: Pluto’s diameter is ~2,377 km.

674. Pluto’s mass is about:  

a) 0.0022 times Earth ✅  

b) 0.1 times Earth  

c) 0.01 times Earth  

d) 0.5 times Earth  

Explanation: Pluto’s mass is ~0.22% of Earth’s.

675. Pluto’s gravity is:  

a) 0.62 m/s² ✅  

b) 9.8 m/s²  

c) 3.7 m/s²  

d) 24.8 m/s²  

Explanation: Pluto’s gravity is ~6% of Earth’s.

676. Pluto’s escape velocity is:  

a) 1.2 km/s ✅  

b) 11.2 km/s  

c) 5 km/s  

d) 35 km/s  

Explanation: Pluto’s escape velocity is ~1.2 km/s.

677. Pluto’s average distance from the Sun is:  

a) 5.9 billion km ✅  

b) 4.5 billion km  

c) 2.87 billion km  

d) 1.43 billion km  

Explanation: Pluto orbits at ~5.9 billion km.

678. Pluto’s orbital period is:  

a) 248 years ✅  

b) 165 years  

c) 84 years  

d) 29.5 years  

Explanation: Pluto completes one orbit in ~248 Earth years.

679. Pluto’s rotation period is:  

a) 6.4 Earth days ✅  

b) 24 hours  

c) 10 hours  

d) 59 days  

Explanation: Pluto rotates once in ~6.4 Earth days.

680. Pluto’s axial tilt is:  

a) 122.5° ✅  

b) 23.5°  

c) 98°  

d) 3.1°  

Explanation: Pluto’s axis is tilted ~122.5°, causing extreme seasons.

681. Pluto’s atmosphere is mostly:  

a) Nitrogen ✅  

b) Oxygen  

c) Carbon dioxide  

d) Hydrogen  

Explanation: Pluto’s atmosphere is ~99% nitrogen.

682. Pluto’s atmosphere contains:  

a) Methane ✅  

b) Oxygen  

c) Nitrogen  

d) Argon  

Explanation: Methane is present in Pluto’s atmosphere.

683. Pluto’s atmosphere contains:  

a) Carbon monoxide ✅  

b) Oxygen  

c) Nitrogen  

d) Argon  

Explanation: Carbon monoxide is present in Pluto’s atmosphere.

684. Pluto’s average temperature is:  

a) -229 °C ✅  

b) -178 °C  

c) -145 °C  

d) 15 °C  

Explanation: Pluto is extremely cold.

685. Pluto’s albedo (reflectivity) is:  

a) 0.52 ✅  

b) 0.3  

c) 0.12  

d) 0.65  

Explanation: Pluto reflects ~52% of sunlight.

686. Pluto has ______ moons.  

a) 5 ✅  

b) 2  

c) 10  

d) 27  

Explanation: Pluto has five known moons.

687. Pluto’s largest moon is:  

a) Charon ✅  

b) Nix  

c) Hydra  

d) Styx  

Explanation: Charon is Pluto’s largest moon.

688. Pluto and Charon are unique because:  

a) They form a binary system ✅  

b) They share rings  

c) They have identical atmospheres  

d) They rotate retrograde  

Explanation: Pluto and Charon orbit a common barycenter.

689. Pluto’s moon Nix is:  

a) Small and irregular ✅  

b) Large and spherical  

c) Volcanic  

d) Icy  

Explanation: Nix is a small irregular moon.

690. Pluto’s moon Hydra is:  

a) Small and irregular ✅  

b) Large and spherical  

c) Volcanic  

d) Icy  

Explanation: Hydra is a small irregular moon.

691. Pluto’s moon Kerberos is:  

a) Small and irregular ✅  

b) Large and spherical  

c) Volcanic  

d) Icy  

Explanation: Kerberos is a small irregular moon.

692. Pluto’s moon Styx is:  

a) Small and irregular ✅  

b) Large and spherical  

c) Volcanic  

d) Icy  

Explanation: Styx is a small irregular moon.

693. Pluto’s orbit is:  

a) Highly elliptical ✅  

b) Circular  

c) Tilted  

d) Retrograde  

Explanation: Pluto’s orbit is highly elliptical.

694. Pluto’s orbital eccentricity is:  

a) 0.25 ✅  

b) 0.046  

c) 0.093  

d) 0.009  

Explanation: Pluto’s orbit is very eccentric.

695. Pluto’s perihelion distance is:  

a) 4.44 billion km ✅  

b) 5.9 billion km  

c) 2.87 billion km  

d) 1.43 billion km  

Explanation: Pluto’s closest distance to Sun is ~4.44 billion km.

696. Pluto’s aphelion distance is:  

a) 7.38 billion km ✅  

b) 5.9 billion km  

c) 2.87 billion km  

d) 1.43 billion km  

Explanation: Pluto’s farthest distance from Sun is ~7.38 billion km.

697. Pluto’s rotation direction is:  

a) Retrograde ✅  

b) Prograde  

c) Tilted  

d) None  

Explanation: Pluto rotates in retrograde motion.

698. Pluto’s revolution direction is:  

a) Counterclockwise ✅  

b) Clockwise  

c) Retrograde  

d) None  

Explanation: Pluto revolves counterclockwise around the Sun.

699. Pluto’s surface contains:  

a) Nitrogen ice ✅  

b) Methane lakes  

c) Water oceans  

d) Volcanoes  

Explanation: Pluto’s surface is covered with nitrogen ice.

700. Pluto’s surface also contains:  

a) Methane ice ✅  

b) Oxygen  

c) Nitrogen gas  

d) Argon  

Explanation: Methane ice is present on Pluto’s surface.

701. Pluto’s surface also contains:  

a) Carbon monoxide ice ✅  

b) Oxygen  

c) Nitrogen gas  

d) Argon  

Explanation: Carbon monoxide ice is present on Pluto’s surface.

702. Pluto’s surface features include:  

a) Mountains of water ice ✅  

b) Volcanoes  

c) Oceans  

d) Forests  

Explanation: Pluto has mountains made of water ice.

703. Pluto’s heart-shaped region is called:  

a) Tombaugh Regio ✅  

b) Valles Marineris  

c) Olympus Mons  

d) Caloris Basin  

Explanation: Tombaugh Regio is a bright heart-shaped area.

704. Pluto’s Sputnik Planitia is:  

a) Ice plain ✅  

b) Volcano  

c) Canyon  

d) Crater  

Explanation: Sputnik Planitia is a nitrogen ice plain.

705. Pluto’s atmosphere expands when:  

a) It approaches perihelion ✅  

b) It reaches aphelion  

c) It rotates retrograde  

d) It tilts  

Explanation: Pluto’s atmosphere expands when closer to the Sun.

706. Pluto’s atmosphere collapses when:  

a) It reaches aphelion ✅  

b) It approaches perihelion  

c) It rotates retrograde  

d) It tilts  

Explanation: Pluto’s atmosphere collapses when farther from the Sun.

707. Pluto’s average density is:  

a) 1.86 g/cm³ ✅  

b) 5.51 g/cm³  

c) 3.93 g/cm³  

d) 0.7 g/cm³  

Explanation: Pluto’s density is ~1.86 g/cm³.

708. Pluto’s magnetic field is:  

a) Unknown/weak ✅  

b) Strong like Jupiter  

c) Absent  

d) Same as Earth  

Explanation: Pluto’s magnetic field is weak or absent.

709. Pluto’s orbit is inclined by:  

a) 17° ✅  

b) 23.5°  

c) 7°  

d) 3.1°  

Explanation: Pluto’s orbit is tilted ~17° to the ecliptic.

710. Pluto’s revolution period is:  

a) 248 years ✅  

b) 165 years  

c) 84 years  

d) 29.5 years  

Explanation: Pluto completes one orbit in ~248 Earth years.

711. Comets are composed mainly of:  

a) Ice and dust ✅  

b) Rock only  

c) Gas only  

d) Metal  

Explanation: Comets are icy bodies with dust and rock.

712. Comets are often called:  

a) Dirty snowballs ✅  

b) Gas giants  

c) Shooting stars  

d) Dwarf planets  

Explanation: Comets are nicknamed “dirty snowballs.”

713. Comets originate mostly from:  

a) Kuiper Belt and Oort Cloud ✅  

b) Asteroid Belt  

c) Saturn’s rings  

d) Earth’s orbit  

Explanation: Comets come from the Kuiper Belt and Oort Cloud.

714. The bright tail of a comet is caused by:  

a) Solar wind ✅  

b) Gravity  

c) Rotation  

d) Magnetism  

Explanation: Solar wind pushes particles away, forming the tail.

715. Comet tails always point:  

a) Away from the Sun ✅  

b) Toward the Sun  

c) Along orbit  

d) Randomly  

Explanation: Solar wind forces tails away from the Sun.

716. Comet nuclei are typically:  

a) Small, a few km across ✅  

b) Thousands of km  

c) Larger than planets  

d) Same as moons  

Explanation: Comet nuclei are usually a few kilometers wide.

717. Comet orbits are usually:  

a) Highly elliptical ✅  

b) Circular  

c) Tilted  

d) Retrograde  

Explanation: Comets have highly elliptical orbits.

718. Short-period comets originate from:  

a) Kuiper Belt ✅  

b) Oort Cloud  

c) Asteroid Belt  

d) Saturn’s rings  

Explanation: Short-period comets come from the Kuiper Belt.

719. Long-period comets originate from:  

a) Oort Cloud ✅  

b) Kuiper Belt  

c) Asteroid Belt  

d) Mars orbit  

Explanation: Long-period comets come from the Oort Cloud.

720. Comet Halley is a:  

a) Short-period comet ✅  

b) Long-period comet  

c) Asteroid  

d) Dwarf planet  

Explanation: Halley’s Comet has a 76-year period.

721. Comet Hale-Bopp is a:  

a) Long-period comet ✅  

b) Short-period comet  

c) Asteroid  

d) Dwarf planet  

Explanation: Hale-Bopp has a long orbital period.

722. Comet tails are of two types:  

a) Ion tail and dust tail ✅  

b) Gas tail and rock tail  

c) Ice tail and fire tail  

d) None  

Explanation: Comets have ion and dust tails.

723. The ion tail is formed by:  

a) Solar wind ✅  

b) Gravity  

c) Rotation  

d) Magnetism  

Explanation: Solar wind creates the ion tail.

724. The dust tail is formed by:  

a) Radiation pressure ✅  

b) Gravity  

c) Rotation  

d) Magnetism  

Explanation: Sunlight pushes dust particles, forming the dust tail.

725. Comet nuclei are made of:  

a) Ice, dust, rock ✅  

b) Gas only  

c) Metal only  

d) Lava  

Explanation: Comet nuclei contain ice, dust, and rock.

726. Comets become visible when:  

a) Near the Sun ✅  

b) Near Earth  

c) Near Jupiter  

d) Near Saturn  

Explanation: Heat from the Sun makes comets visible.

727. The coma of a comet is:  

a) Cloud of gas and dust ✅  

b) Rocky core  

c) Ice cap  

d) Atmosphere  

Explanation: The coma surrounds the nucleus.

728. Comet tails can extend:  

a) Millions of km ✅  

b) Hundreds of km  

c) Thousands of km  

d) Few meters  

Explanation: Comet tails can stretch millions of kilometers.

729. Comet nuclei are usually:  

a) Irregular in shape ✅  

b) Perfect spheres  

c) Cubes  

d) Flat discs  

Explanation: Comet nuclei are irregularly shaped.

730. Comets are part of:  

a) Solar System ✅  

b) Galaxy only  

c) Interstellar medium  

d) None  

Explanation: Comets belong to the Solar System.

731. Comets can impact:  

a) Planets ✅  

b) Stars only  

c) Moons only  

d) None  

Explanation: Comets can collide with planets.

732. Comets provide clues about:  

a) Early Solar System ✅  

b) Earth’s oceans only  

c) Current atmosphere  

d) Volcanoes  

Explanation: Comets preserve early Solar System material.

733. Comet Shoemaker-Levy 9 impacted:  

a) Jupiter ✅  

b) Earth  

c) Saturn  

d) Mars  

Explanation: Shoemaker-Levy 9 collided with Jupiter in 1994.

734. Comet Encke is a:  

a) Short-period comet ✅  

b) Long-period comet  

c) Asteroid  

d) Dwarf planet  

Explanation: Encke has a short orbital period.

735. Comet Swift-Tuttle is:  

a) Parent of Perseid meteor shower ✅  

b) Parent of Leonid meteor shower  

c) Parent of Geminid meteor shower  

d) Parent of Orionid meteor shower  

Explanation: Swift-Tuttle produces the Perseids.

736. Comet Tempel-Tuttle is:  

a) Parent of Leonid meteor shower ✅  

b) Parent of Perseid meteor shower  

c) Parent of Geminid meteor shower  

d) Parent of Orionid meteor shower  

Explanation: Tempel-Tuttle produces the Leonids.

737. Comet Halley is:  

a) Parent of Orionid meteor shower ✅  

b) Parent of Perseid meteor shower  

c) Parent of Leonid meteor shower  

d) Parent of Geminid meteor shower  

Explanation: Halley produces the Orionids.

738. Comet nuclei are dark because:  

a) Covered with dust ✅  

b) Covered with ice only  

c) Covered with lava  

d) Covered with gas  

Explanation: Dust makes comet nuclei dark.

739. Comets lose mass due to:  

a) Sublimation ✅  

b) Gravity  

c) Rotation  

d) Magnetism  

Explanation: Ice sublimates, reducing comet mass.

740. Comets are studied by missions like:  

a) Rosetta ✅  

b) Voyager  

c) Cassini  

d) Hubble  

Explanation: ESA’s Rosetta mission studied Comet 67P.

741. Asteroids are composed mainly of:  

a) Rock and metal ✅  

b) Ice only  

c) Gas only  

d) Dust only  

Explanation: Asteroids are rocky and metallic bodies.

742. Asteroids are often called:  

a) Minor planets ✅  

b) Dwarf planets  

c) Shooting stars  

d) Comets  

Explanation: Asteroids are sometimes referred to as minor planets.

743. Most asteroids are found in:  

a) Asteroid Belt ✅  

b) Kuiper Belt  

c) Oort Cloud  

d) Saturn’s rings  

Explanation: The Asteroid Belt lies between Mars and Jupiter.

744. The largest asteroid is:  

a) Ceres ✅  

b) Vesta  

c) Pallas  

d) Hygiea  

Explanation: Ceres is the largest asteroid and classified as a dwarf planet.

745. The second-largest asteroid is:  

a) Vesta ✅  

b) Pallas  

c) Hygiea  

d) Ceres  

Explanation: Vesta is the second-largest asteroid.

746. The third-largest asteroid is:  

a) Pallas ✅  

b) Vesta  

c) Hygiea  

d) Ceres  

Explanation: Pallas is the third-largest asteroid.

747. The fourth-largest asteroid is:  

a) Hygiea ✅  

b) Vesta  

c) Pallas  

d) Ceres  

Explanation: Hygiea is the fourth-largest asteroid.

748. Asteroids are classified into types based on:  

a) Composition ✅  

b) Size only  

c) Orbit only  

d) Shape only  

Explanation: Asteroids are classified by composition.

749. C-type asteroids are:  

a) Carbon-rich ✅  

b) Metallic  

c) Rocky  

d) Icy  

Explanation: C-type asteroids are carbonaceous.

750. S-type asteroids are:  

a) Silicate-rich ✅  

b) Carbon-rich  

c) Metallic  

d) Icy  

Explanation: S-type asteroids are silicate-rich.

751. M-type asteroids are:  

a) Metallic ✅  

b) Carbon-rich  

c) Silicate-rich  

d) Icy  

Explanation: M-type asteroids are metallic.

752. Near-Earth asteroids are:  

a) Close to Earth’s orbit ✅  

b) In Kuiper Belt  

c) In Oort Cloud  

d) In Saturn’s rings  

Explanation: Near-Earth asteroids approach Earth’s orbit.

753. Trojan asteroids share orbit with:  

a) Jupiter ✅  

b) Saturn  

c) Earth  

d) Mars  

Explanation: Trojan asteroids share Jupiter’s orbit.

754. Some Trojan asteroids also share orbit with:  

a) Earth ✅  

b) Saturn  

c) Mars  

d) Venus  

Explanation: Earth has Trojan asteroids too.

755. Asteroids can cause:  

a) Impact craters ✅  

b) Volcanoes  

c) Auroras  

d) Magnetism  

Explanation: Asteroids create craters when they impact planets.

756. The asteroid that caused dinosaur extinction is:  

a) Chicxulub impactor ✅  

b) Vesta  

c) Ceres  

d) Pallas  

Explanation: The Chicxulub asteroid struck Earth ~66 million years ago.

757. Asteroids are studied by missions like:  

a) Dawn ✅  

b) Voyager  

c) Cassini  

d) Hubble  

Explanation: NASA’s Dawn mission studied Vesta and Ceres.

758. Asteroids are irregular because:  

a) Small size ✅  

b) Gravity strong  

c) Rotation fast  

d) Magnetism  

Explanation: Small size prevents them from becoming spherical.

759. Asteroids can be mined for:  

a) Metals ✅  

b) Ice only  

c) Gas only  

d) Dust only  

Explanation: Asteroids contain valuable metals.

760. Asteroids provide clues about:  

a) Early Solar System ✅  

b) Earth’s oceans only  

c) Current atmosphere  

d) Volcanoes  

Explanation: Asteroids preserve early Solar System material.

761. The asteroid belt lies between:  

a) Mars and Jupiter ✅  

b) Earth and Mars  

c) Jupiter and Saturn  

d) Saturn and Uranus  

Explanation: The asteroid belt is between Mars and Jupiter.

762. The asteroid belt contains:  

a) Millions of asteroids ✅  

b) Thousands only  

c) Billions  

d) Dozens  

Explanation: Millions of asteroids exist in the belt.

763. Asteroids are remnants of:  

a) Early planet formation ✅  

b) Comets  

c) Moons  

d) Stars  

Explanation: Asteroids are leftover building blocks of planets.

764. Some asteroids have:  

a) Moons ✅  

b) Atmospheres  

c) Oceans  

d) Rings  

Explanation: Certain asteroids have small moons.

765. Some asteroids have:  

a) Rings ✅  

b) Atmospheres  

c) Oceans  

d) Forests  

Explanation: A few asteroids have ring systems.

766. Asteroids are classified as:  

a) C-type, S-type, M-type ✅  

b) A-type, B-type, D-type  

c) X-type, Y-type, Z-type  

d) None  

Explanation: Main asteroid types are C, S, and M.

767. Asteroids can be:  

a) Binary systems ✅  

b) Single only  

c) Triple systems only  

d) None  

Explanation: Some asteroids exist as binary pairs.

768. Asteroids are irregular in:  

a) Shape ✅  

b) Orbit only  

c) Composition only  

d) None  

Explanation: Asteroids are irregularly shaped.

769. Asteroids are studied to:  

a) Prevent impacts ✅  

b) Create volcanoes  

c) Cause auroras  

d) Increase magnetism  

Explanation: Studying asteroids helps prevent impact hazards.

770. Asteroids are part of:  

a) Solar System ✅  

b) Galaxy only  

c) Interstellar medium  

d) None  

Explanation: Asteroids belong to the Solar System.

771. Meteoroids are:  

a) Small rocky or metallic bodies ✅  

b) Large planets  

c) Gas giants  

d) Dwarf planets  

Explanation: Meteoroids are small rocky or metallic objects in space.

772. Meteors are:  

a) Meteoroids entering Earth’s atmosphere ✅  

b) Moons  

c) Comets  

d) Asteroids  

Explanation: Meteors are meteoroids burning in Earth’s atmosphere.

773. Meteorites are:  

a) Meteoroids that reach Earth’s surface ✅  

b) Comets  

c) Moons  

d) Stars  

Explanation: Meteorites are meteoroids that survive atmospheric entry.

774. Meteoroids are smaller than:  

a) Asteroids ✅  

b) Moons  

c) Comets  

d) Planets  

Explanation: Meteoroids are smaller fragments compared to asteroids.

775. Meteors are often called:  

a) Shooting stars ✅  

b) Comets  

c) Planets  

d) Moons  

Explanation: Meteors are nicknamed “shooting stars.”

776. Meteor showers occur when:  

a) Earth passes through comet debris ✅  

b) Earth passes through asteroid belt  

c) Earth rotates retrograde  

d) Earth tilts  

Explanation: Meteor showers happen when Earth crosses comet trails.

777. The Perseid meteor shower is caused by:  

a) Comet Swift-Tuttle ✅  

b) Comet Halley  

c) Comet Encke  

d) Comet Tempel-Tuttle  

Explanation: Perseids come from Comet Swift-Tuttle.

778. The Leonid meteor shower is caused by:  

a) Comet Tempel-Tuttle ✅  

b) Comet Halley  

c) Comet Encke  

d) Comet Swift-Tuttle  

Explanation: Leonids come from Comet Tempel-Tuttle.

779. The Orionid meteor shower is caused by:  

a) Comet Halley ✅  

b) Comet Swift-Tuttle  

c) Comet Encke  

d) Comet Tempel-Tuttle  

Explanation: Orionids come from Comet Halley.

780. The Geminid meteor shower is caused by:  

a) Asteroid 3200 Phaethon ✅  

b) Comet Halley  

c) Comet Encke  

d) Comet Swift-Tuttle  

Explanation: Geminids come from asteroid 3200 Phaethon.

781. The Quadrantid meteor shower is caused by:  

a) Asteroid 2003 EH1 ✅  

b) Comet Halley  

c) Comet Encke  

d) Comet Swift-Tuttle  

Explanation: Quadrantids come from asteroid 2003 EH1.

782. Meteor showers are named after:  

a) Constellations ✅  

b) Planets  

c) Moons  

d) Stars  

Explanation: Meteor showers are named after the constellation they appear in.

783. Meteoroids can be fragments of:  

a) Asteroids or comets ✅  

b) Stars  

c) Moons  

d) Planets  

Explanation: Meteoroids often come from asteroids or comets.

784. Meteors burn due to:  

a) Friction with atmosphere ✅  

b) Gravity  

c) Rotation  

d) Magnetism  

Explanation: Friction causes meteors to glow.

785. Meteorites can be classified as:  

a) Stony, iron, stony-iron ✅  

b) Gas, liquid, solid  

c) Rocky, icy, metallic  

d) None  

Explanation: Meteorites are stony, iron, or stony-iron.

786. Stony meteorites are:  

a) Silicate-rich ✅  

b) Metallic  

c) Carbon-rich  

d) Icy  

Explanation: Stony meteorites are made of silicates.

787. Iron meteorites are:  

a) Metallic ✅  

b) Silicate-rich  

c) Carbon-rich  

d) Icy  

Explanation: Iron meteorites are composed of iron and nickel.

788. Stony-iron meteorites are:  

a) Mixture of silicates and metals ✅  

b) Pure silicates  

c) Pure metals  

d) Pure carbon  

Explanation: Stony-iron meteorites are mixed composition.

789. Meteoroids can range in size from:  

a) Grains to meters ✅  

b) Kilometers only  

c) Thousands of km  

d) Same as planets  

Explanation: Meteoroids vary from tiny grains to meter-sized.

790. Large meteoroid impacts can cause:  

a) Craters ✅  

b) Volcanoes  

c) Auroras  

d) Magnetism  

Explanation: Large meteoroids create craters.

791. Famous meteorite impact crater in Arizona is:  

a) Barringer Crater ✅  

b) Chicxulub Crater  

c) Valles Marineris  

d) Tycho Crater  

Explanation: Barringer Crater is a meteorite impact site.

792. The Chicxulub Crater was caused by:  

a) Asteroid/meteoroid impact ✅  

b) Volcano  

c) Earthquake  

d) Flood  

Explanation: Chicxulub impact caused dinosaur extinction.

793. Meteors that explode in atmosphere are called:  

a) Bolides ✅  

b) Fireballs  

c) Shooting stars  

d) Meteorites  

Explanation: Bolides are meteors that explode in the atmosphere.

794. Bright meteors are called:  

a) Fireballs ✅  

b) Bolides  

c) Shooting stars  

d) Meteorites  

Explanation: Fireballs are exceptionally bright meteors.

795. Meteor showers occur annually because:  

a) Earth crosses same debris trail ✅  

b) Earth rotates retrograde  

c) Earth tilts  

d) Earth’s orbit changes  

Explanation: Earth crosses comet debris at the same time each year.

796. Meteoroids traveling through space are:  

a) Small fragments ✅  

b) Large planets  

c) Gas giants  

d) Stars  

Explanation: Meteoroids are small fragments in space.

797. Meteor showers are best observed:  

a) At night ✅  

b) During day  

c) At noon  

d) At sunrise  

Explanation: Meteor showers are visible at night.

798. Meteor showers peak when:  

a) Earth passes densest debris ✅  

b) Earth rotates fastest  

c) Earth tilts  

d) Earth’s orbit changes  

Explanation: Showers peak when Earth crosses densest comet debris.

799. Meteorites provide clues about:  

a) Early Solar System ✅  

b) Earth’s oceans only  

c) Current atmosphere  

d) Volcanoes  

Explanation: Meteorites preserve early Solar System material.

800. Meteorites can contain:  

a) Organic compounds ✅  

b) Oxygen only  

c) Nitrogen only  

d) Argon only  

Explanation: Some meteorites contain organic compounds.

801. The Universe is defined as:  

a) All space, time, matter, and energy ✅  

b) Only galaxies  

c) Only stars  

d) Only planets  

Explanation: The Universe includes everything that exists.

802. The age of the Universe is approximately:  

a) 13.8 billion years ✅  

b) 4.5 billion years  

c) 10 billion years  

d) 20 billion years  

Explanation: The Universe is ~13.8 billion years old.

803. The Big Bang Theory explains:  

a) Origin of the Universe ✅  

b) Origin of Earth  

c) Origin of Sun  

d) Origin of Moon  

Explanation: The Big Bang describes the Universe’s beginning.

804. Evidence for the Big Bang includes:  

a) Cosmic Microwave Background ✅  

b) Volcanoes  

c) Earthquakes  

d) Magnetism  

Explanation: CMB radiation supports the Big Bang.

805. Another evidence for the Big Bang is:  

a) Redshift of galaxies ✅  

b) Blue shift of galaxies  

c) Rotation of Earth  

d) Gravity  

Explanation: Redshift shows galaxies moving away.

806. The Universe is:  

a) Expanding ✅  

b) Contracting  

c) Static  

d) Rotating  

Explanation: The Universe is expanding.

807. The expansion of the Universe was discovered by:  

a) Edwin Hubble ✅  

b) Isaac Newton  

c) Galileo Galilei  

d) Albert Einstein  

Explanation: Hubble discovered galaxy redshift.

808. The Hubble’s Law relates:  

a) Galaxy velocity and distance ✅  

b) Mass and gravity  

c) Rotation and tilt  

d) Magnetism and heat  

Explanation: Hubble’s Law shows galaxies move faster when farther.

809. The observable Universe extends about:  

a) 93 billion light years ✅  

b) 13.8 billion light years  

c) 50 billion light years  

d) 200 billion light years  

Explanation: The observable Universe is ~93 billion light years across.

810. The Universe contains:  

a) Galaxies, stars, planets ✅  

b) Earth only  

c) Sun only  

d) Moons only  

Explanation: The Universe contains all cosmic structures.

811. Galaxies are:  

a) Collections of stars, gas, dust ✅  

b) Single stars  

c) Planets only  

d) Moons only  

Explanation: Galaxies are massive star systems.

812. The Milky Way is:  

a) Our galaxy ✅  

b) A star  

c) A planet  

d) A nebula  

Explanation: The Milky Way is the galaxy we live in.

813. The Milky Way is a:  

a) Spiral galaxy ✅  

b) Elliptical galaxy  

c) Irregular galaxy  

d) Ring galaxy  

Explanation: The Milky Way is a barred spiral galaxy.

814. The Milky Way contains about:  

a) 100–400 billion stars ✅  

b) 1 million stars  

c) 10 billion stars  

d) 1 trillion stars  

Explanation: The Milky Way has hundreds of billions of stars.

815. The center of the Milky Way contains:  

a) Supermassive black hole ✅  

b) Sun  

c) Earth  

d) Moon  

Explanation: Sagittarius A* is a supermassive black hole.

816. The nearest galaxy to the Milky Way is:  

a) Andromeda ✅  

b) Triangulum  

c) Large Magellanic Cloud  

d) Small Magellanic Cloud  

Explanation: Andromeda is the closest large galaxy.

817. The Local Group contains:  

a) Milky Way, Andromeda, Triangulum ✅  

b) Only Milky Way  

c) Only Andromeda  

d) Only Triangulum  

Explanation: The Local Group is a small cluster of galaxies.

818. Galaxy clusters are:  

a) Groups of galaxies ✅  

b) Groups of stars  

c) Groups of planets  

d) Groups of moons  

Explanation: Galaxy clusters contain many galaxies.

819. Superclusters are:  

a) Groups of galaxy clusters ✅  

b) Groups of stars  

c) Groups of planets  

d) Groups of moons  

Explanation: Superclusters are the largest structures.

820. The largest known structure in the Universe is:  

a) Hercules–Corona Borealis Great Wall ✅  

b) Milky Way  

c) Andromeda  

d) Local Group  

Explanation: This Great Wall is the largest known cosmic structure.

821. Dark matter makes up about:  

a) 27% of Universe ✅  

b) 5%  

c) 50%  

d) 70%  

Explanation: Dark matter is ~27% of the Universe.

822. Dark energy makes up about:  

a) 68% of Universe ✅  

b) 5%  

c) 27%  

d) 50%  

Explanation: Dark energy drives cosmic expansion.

823. Ordinary matter makes up about:  

a) 5% of Universe ✅  

b) 27%  

c) 68%  

d) 50%  

Explanation: Ordinary matter is ~5% of the Universe.

824. Dark matter is detected by:  

a) Gravitational effects ✅  

b) Light emission  

c) Magnetism  

d) Heat radiation  

Explanation: Dark matter is invisible but affects gravity.

825. Dark energy is detected by:  

a) Accelerating expansion ✅  

b) Heat radiation  

c) Magnetism  

d) Rotation  

Explanation: Dark energy is inferred from expansion.

826. The Universe began with:  

a) Big Bang ✅  

b) Big Crunch  

c) Steady State  

d) Oscillation  

Explanation: The Big Bang is the accepted origin.

827. The fate of the Universe may be:  

a) Big Freeze ✅  

b) Big Crunch  

c) Big Rip  

d) All possible  

Explanation: The most likely fate is Big Freeze.

828. The Big Freeze means:  

a) Universe cools and expands forever ✅  

b) Universe collapses  

c) Universe rips apart  

d) Universe rotates  

Explanation: Expansion leads to cooling and freezing.

829. Another possible fate is:  

a) Big Crunch ✅  

b) Big Freeze  

c) Big Rip  

d) Steady State  

Explanation: Big Crunch means Universe collapses.

830. Another possible fate is:  

a) Big Rip ✅  

b) Big Freeze  

c) Big Crunch  

d) Steady State  

Explanation: Big Rip means Universe tears apart.

831. The Steady State Theory claimed:  

a) Universe is eternal and unchanging ✅  

b) Universe began with Big Bang  

c) Universe collapses  

d) Universe rotates  

Explanation: Steady State suggested continuous creation.

832. The Steady State Theory was disproved by:  

a) Cosmic Microwave Background ✅  

b) Volcanoes  

c) Earthquakes  

d) Magnetism  

Explanation: CMB disproved Steady State.

833. The Universe contains billions of:  

a) Galaxies ✅  

b) Moons  

c) Planets  

d) Suns only  

Explanation: Billions of galaxies exist.

834. The Universe contains trillions of:  

a) Stars ✅  

b) Moons  

c) Planets  

d) Suns only  

Explanation: Trillions of stars exist.

835. The Universe contains billions of:  

a) Planets ✅  

b) Moons  

c) Suns only  

d) Galaxies only  

Explanation: Billions of planets exist.

836. The Universe contains billions of:  

a) Black holes ✅  

b) Moons  

c) Suns only  

d) Galaxies only  

Explanation: Billions of black holes exist.

837. The Universe is studied by:  

a) Telescopes ✅  

b) Microscopes  

c) Satellites only  

d) Volcanoes  

Explanation: Telescopes study the Universe.

838. Space telescopes include:  

a) Hubble, James Webb ✅  

b) Galileo, Newton  

c) Cassini, Voyager  

d) Dawn, Rosetta  

Explanation: Hubble and JWST are space telescopes.

839. The James Webb Space Telescope studies:  

a) Infrared Universe ✅  

b) Visible light only  

c) X-rays only  

d) Gamma rays only  

Explanation: JWST observes infrared.

840. The Hubble Space Telescope studies:  

a) Visible and ultraviolet ✅  

b) Infrared only  

c) X-rays only  

d) Gamma rays only  

Explanation: Hubble observes visible and UV light.

841. The Universe is homogeneous and isotropic at:  

a) Large scales ✅  

b) Small scales  

c) Planetary scales  

d) Solar scales  

Explanation: At large scales, Universe is uniform.

842. The Cosmic Microwave Background was discovered in:  

a) 1965 ✅  

b) 1929  

c) 2006  

d) 2015  

Explanation: CMB was discovered by Penzias and Wilson.

843. The CMB temperature is:  

a) 2.7 K ✅  

b) 273 K  

c) 100 K  

d) 0 K  

Explanation: CMB is ~2.7 Kelvin.

844. The Universe’s expansion is:  

a) Accelerating ✅  

b) Slowing  

c) Static  

d) Contracting  

Explanation: Expansion is accelerating due to dark energy.

845. The Universe’s expansion rate is measured by:  

a) Hubble constant ✅  

b) Speed of light  

c) Gravitational constant  

d) Planck constant  

Explanation: The Hubble constant measures the Universe’s expansion rate.

846. The Hubble constant shows:  

a) Galaxies move faster when farther ✅  

b) Galaxies move slower when farther  

c) Galaxies are static  

d) Galaxies rotate retrograde  

Explanation: Hubble’s Law shows velocity increases with distance.

847. The observable Universe is limited by:  

a) Speed of light ✅  

b) Gravity  

c) Rotation  

d) Magnetism  

Explanation: Light speed limits what we can observe.

848. The Universe is homogeneous and isotropic at:  

a) Large scales ✅  

b) Small scales  

c) Planetary scales  

d) Solar scales  

Explanation: At large scales, the Universe is uniform.

849. The Cosmic Microwave Background proves:  

a) Big Bang ✅  

b) Steady State  

c) Big Crunch  

d) Big Rip  

Explanation: CMB is evidence of the Big Bang.

850. The Universe’s fate depends on:  

a) Dark energy ✅  

b) Gravity only  

c) Rotation  

d) Magnetism  

Explanation: Dark energy determines the Universe’s ultimate fate.

851. Which spacecraft entered its extended mission around Jupiter’s moon Io in 2025?  

a) Juno ✅  

b) Cassini  

c) Voyager 2  

d) New Horizons  

Explanation: NASA’s Juno began extended flybys of Io in 2025.

852. Which Indian mission is planned to study the Sun from L1 point?  

a) Aditya-L1 ✅  

b) Chandrayaan-3  

c) Mangalyaan  

d) Shukrayaan  

Explanation: Aditya-L1 is India’s solar observatory mission.

853. Which rover continues to explore Mars in 2025?  

a) Perseverance ✅  

b) Curiosity  

c) Spirit  

d) Opportunity  

Explanation: NASA’s Perseverance rover is active on Mars.

854. Which helicopter is flying on Mars alongside Perseverance?  

a) Ingenuity ✅  

b) Dragonfly  

c) MAVEN  

d) Phoenix  

Explanation: Ingenuity is the first powered aircraft on Mars.

855. Which mission is planned to explore Jupiter’s icy moon Europa?  

a) Europa Clipper ✅  

b) Juno  

c) Cassini  

d) Voyager 1  

Explanation: Europa Clipper will study Europa’s ocean and habitability.

856. Which mission is planned to explore Saturn’s moon Titan?  

a) Dragonfly ✅  

b) Cassini  

c) Perseverance  

d) Voyager 2  

Explanation: Dragonfly will send a rotorcraft to Titan.

857. Which telescope launched in 2021 continues to provide deep space images in 2025?  

a) James Webb Space Telescope ✅  

b) Hubble  

c) Spitzer  

d) Kepler  

Explanation: JWST observes the Universe in infrared.

858. Which asteroid mission returned samples to Earth in 2023, studied in 2025?  

a) OSIRIS-REx ✅  

b) Hayabusa2  

c) Dawn  

d) Rosetta  

Explanation: OSIRIS-REx brought back samples from asteroid Bennu.

859. Which Indian mission is proposed to study Venus?  

a) Shukrayaan ✅  

b) Chandrayaan-2  

c) Aditya-L1  

d) Mangalyaan  

Explanation: Shukrayaan is ISRO’s planned Venus mission.

860. Which spacecraft is the farthest human-made object in 2025?  

a) Voyager 1 ✅  

b) Voyager 2  

c) New Horizons  

d) Pioneer 10  

Explanation: Voyager 1 is the most distant spacecraft.

861. Which spacecraft continues to study Saturn’s rings through archived data in 2025?  

a) Cassini ✅  

b) Juno  

c) Voyager 2  

d) Dragonfly  

Explanation: Cassini’s archived data is still analyzed.

862. Which mission studies Mars’s atmosphere from orbit?  

a) MAVEN ✅  

b) Perseverance  

c) Curiosity  

d) Phoenix  

Explanation: MAVEN studies Mars’s upper atmosphere.

863. Which spacecraft flew past Pluto in 2015 and continues its extended mission?  

a) New Horizons ✅  

b) Voyager 2  

c) Cassini  

d) Dawn  

Explanation: New Horizons continues exploring Kuiper Belt objects.

864. Which mission studies Mercury?  

a) BepiColombo ✅  

b) MESSENGER  

c) Voyager 1  

d) Chandrayaan-2  

Explanation: BepiColombo is a joint ESA–JAXA mission to Mercury.

865. Which mission studies the Sun’s outer corona?  

a) Parker Solar Probe ✅  

b) Aditya-L1  

c) Hubble  

d) Dragonfly  

Explanation: Parker Solar Probe flies close to the Sun’s corona.

866. Which telescope is still operational in Earth orbit in 2025?  

a) Hubble ✅  

b) Kepler  

c) Spitzer  

d) Chandra  

Explanation: Hubble continues to operate alongside JWST.

867. Which mission studies Jupiter’s moons Ganymede, Callisto, and Europa?  

a) JUICE ✅  

b) Juno  

c) Cassini  

d) Voyager 1  

Explanation: ESA’s JUICE mission launched to study Jupiter’s icy moons.

868. Which mission studies Saturn’s moon Titan with radar data?  

a) Cassini ✅  

b) Dragonfly  

c) Perseverance  

d) MAVEN  

Explanation: Cassini provided radar maps of Titan.

869. Which spacecraft studies the Kuiper Belt beyond Pluto?  

a) New Horizons ✅  

b) Voyager 2  

c) Cassini  

d) Dawn  

Explanation: New Horizons continues exploring Kuiper Belt objects.

870. Which mission studies Earth’s climate from space?  

a) NASA Earth Observing System ✅  

b) Juno  

c) MAVEN  

d) Dragonfly  

Explanation: EOS satellites monitor Earth’s climate and atmosphere.

871. Assertion (A): Venus is hotter than Mercury.  

Reason (R): Venus has a thick atmosphere of carbon dioxide causing greenhouse effect.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Venus’s greenhouse effect makes it hotter than Mercury.

872. Which planet has the fastest winds in the Solar System?  

a) Neptune ✅  

b) Saturn  

c) Jupiter  

d) Uranus  

Explanation: Neptune’s winds reach ~2,100 km/h.

873. Which mission provided radar maps of Saturn’s moon Titan?  

a) Cassini ✅  

b) Dragonfly  

c) Perseverance  

d) MAVEN  

Explanation: Cassini mapped Titan’s surface with radar.

874. Which planet rotates on its side with an axial tilt of ~98°?  

a) Uranus ✅  

b) Neptune  

c) Saturn  

d) Venus  

Explanation: Uranus rotates almost horizontally.

875. Which spacecraft is currently the farthest human-made object from Earth?  

a) Voyager 1 ✅  

b) Voyager 2  

c) New Horizons  

d) Pioneer 10  

Explanation: Voyager 1 is the most distant spacecraft.

876. Assertion (A): Pluto’s orbit sometimes brings it closer to the Sun than Neptune.  

Reason (R): Pluto’s orbit is highly elliptical.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Pluto’s eccentric orbit crosses inside Neptune’s distance.

877. Which planet has the shortest day (fastest rotation)?  

a) Jupiter ✅  

b) Saturn  

c) Neptune  

d) Earth  

Explanation: Jupiter rotates in ~9.9 hours.

878. Which moon is known for geysers of water vapor?  

a) Enceladus ✅  

b) Titan  

c) Europa  

d) Ganymede  

Explanation: Enceladus ejects water vapor from its surface.

879. Which telescope observes the Universe in infrared wavelengths?  

a) James Webb Space Telescope ✅  

b) Hubble  

c) Chandra  

d) Spitzer  

Explanation: JWST specializes in infrared astronomy.

880. Assertion (A): Mars has seasons like Earth.  

Reason (R): Mars has a similar axial tilt to Earth.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Mars’s tilt (~25°) causes seasons.

881. Which planet has the Great Red Spot storm?  

a) Jupiter ✅  

b) Saturn  

c) Neptune  

d) Uranus  

Explanation: Jupiter’s Great Red Spot is a giant storm.

882. Which moon has retrograde orbit around its planet?  

a) Triton ✅  

b) Titan  

c) Ganymede  

d) Europa  

Explanation: Triton orbits Neptune in retrograde.

883. Which mission studies the Sun’s corona by flying close to it?  

a) Parker Solar Probe ✅  

b) Aditya-L1  

c) Hubble  

d) Dragonfly  

Explanation: Parker Solar Probe flies into the Sun’s corona.

884. Which planet has the lowest average temperature?  

a) Uranus ✅  

b) Neptune  

c) Saturn  

d) Pluto  

Explanation: Uranus is the coldest planet despite being closer than Neptune.

885. Assertion (A): Saturn’s rings are very thin compared to their width.  

Reason (R): Ring particles are spread out in a flat plane.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Saturn’s rings are less than 1 km thick.

886. Which asteroid mission returned samples to Earth from Bennu?  

a) OSIRIS-REx ✅  

b) Hayabusa2  

c) Dawn  

d) Rosetta  

Explanation: OSIRIS-REx brought Bennu samples.

887. Which planet has the slowest rotation (longest day)?  

a) Venus ✅  

b) Mercury  

c) Mars  

d) Earth  

Explanation: Venus rotates once in ~243 Earth days.

888. Which moon is the largest in the Solar System?  

a) Ganymede ✅  

b) Titan  

c) Callisto  

d) Io  

Explanation: Ganymede is the largest moon.

889. Which mission is planned to explore Jupiter’s moon Europa?  

a) Europa Clipper ✅  

b) Juno  

c) Cassini  

d) Voyager 1  

Explanation: Europa Clipper will study Europa’s ocean.

890. Which planet has the highest escape velocity?  

a) Jupiter ✅  

b) Saturn  

c) Neptune  

d) Earth  

Explanation: Jupiter’s escape velocity is ~59.5 km/s.

891. Assertion (A): Light from distant galaxies is redshifted.  

Reason (R): The Universe is expanding.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Expansion stretches light waves, causing redshift.

892. Which telescope discovered the accelerating expansion of the Universe?  

a) Hubble Space Telescope ✅  

b) James Webb  

c) Spitzer  

d) Chandra  

Explanation: Hubble observations of supernovae revealed acceleration.

893. Which mission studies Mercury with ESA–JAXA collaboration?  

a) BepiColombo ✅  

b) MESSENGER  

c) Voyager 2  

d) Dawn  

Explanation: BepiColombo is a joint mission to Mercury.

894. Which mission is designed to explore Jupiter’s icy moons?  

a) JUICE ✅  

b) Juno  

c) Cassini  

d) Voyager 1  

Explanation: ESA’s JUICE mission targets Ganymede, Callisto, and Europa.

895. Assertion (A): The Cosmic Microwave Background supports the Big Bang Theory.  

Reason (R): It is leftover radiation from the early Universe.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: CMB is relic radiation from ~380,000 years after Big Bang.

896. Which mission studies the Sun from L1 point?  

a) Aditya-L1 ✅  

b) Parker Solar Probe  

c) Hubble  

d) Dragonfly  

Explanation: Aditya-L1 is India’s solar observatory at L1.

897. Which mission flies closest to the Sun’s corona?  

a) Parker Solar Probe ✅  

b) Aditya-L1  

c) Hubble  

d) Cassini  

Explanation: Parker Solar Probe dives into the Sun’s corona.

898. Which telescope observes the Universe in infrared wavelengths?  

a) James Webb Space Telescope ✅  

b) Hubble  

c) Chandra  

d) Spitzer  

Explanation: JWST specializes in infrared astronomy.

899. Assertion (A): Neptune has the fastest winds in the Solar System.  

Reason (R): Its atmosphere contains methane and dynamic weather systems.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Neptune’s winds reach ~2,100 km/h due to atmospheric dynamics.

900. Which mission returned samples from asteroid Bennu?  

a) OSIRIS-REx ✅  

b) Hayabusa2  

c) Dawn  

d) Rosetta  

Explanation: OSIRIS-REx delivered Bennu samples to Earth.

901. Which mission studied Saturn and its rings until 2017?  

a) Cassini ✅  

b) Juno  

c) Voyager 2  

d) Dragonfly  

Explanation: Cassini orbited Saturn for 13 years.

902. Which mission studied Pluto in 2015?  

a) New Horizons ✅  

b) Voyager 2  

c) Cassini  

d) Dawn  

Explanation: New Horizons flew past Pluto in 2015.

903. Assertion (A): Uranus is the coldest planet in the Solar System.  

Reason (R): Uranus emits very little internal heat.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Uranus has minimal internal heat compared to other giants.

904. Which mission studied Mars’s atmosphere from orbit?  

a) MAVEN ✅  

b) Perseverance  

c) Curiosity  

d) Phoenix  

Explanation: MAVEN studies Mars’s upper atmosphere.

905. Which mission is planned to explore Saturn’s moon Titan with a rotorcraft?  

a) Dragonfly ✅  

b) Cassini  

c) Perseverance  

d) Voyager 1  

Explanation: Dragonfly will send a drone to Titan.

906. Which telescope continues to operate in Earth orbit alongside JWST?  

a) Hubble ✅  

b) Kepler  

c) Spitzer  

d) Chandra  

Explanation: Hubble still functions in 2025.

907. Assertion (A): Jupiter has the shortest day among planets.  

Reason (R): Jupiter rotates once in ~9.9 hours.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Jupiter’s rapid rotation gives it the shortest day.

908. Which mission studied comet 67P/Churyumov–Gerasimenko?  

a) Rosetta ✅  

b) Dawn  

c) Voyager 2  

d) Cassini  

Explanation: ESA’s Rosetta orbited comet 67P.

909. Which mission studied Vesta and Ceres?  

a) Dawn ✅  

b) Rosetta  

c) Cassini  

d) Juno  

Explanation: NASA’s Dawn mission explored Vesta and Ceres.

910. Which mission studied Jupiter’s atmosphere and magnetosphere?  

a) Juno ✅  

b) Cassini  

c) Voyager 2  

d) Dragonfly  

Explanation: Juno studies Jupiter’s atmosphere and magnetic field.

911. Assertion (A): Earth is the only planet known to support life.  

Reason (R): Earth has liquid water and a protective atmosphere.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Earth’s liquid water and atmosphere sustain life.

912. Which planet has the highest surface temperature?  

a) Venus ✅  

b) Mercury  

c) Mars  

d) Jupiter  

Explanation: Venus’s greenhouse effect makes it the hottest planet.

913. Which moon is believed to have a subsurface ocean beneath its icy crust?  

a) Europa ✅  

b) Titan  

c) Ganymede  

d) Callisto  

Explanation: Europa likely has a liquid ocean under its ice.

914. Assertion (A): The Milky Way is a spiral galaxy.  

Reason (R): It has a central bulge and spiral arms.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: The Milky Way is a barred spiral galaxy.

915. Which mission studied Jupiter’s magnetosphere and atmosphere?  

a) Juno ✅  

b) Cassini  

c) Voyager 2  

d) Dragonfly  

Explanation: Juno is dedicated to Jupiter’s atmosphere and magnetic field.

916. Which planet has the longest orbital period?  

a) Neptune ✅  

b) Uranus  

c) Saturn  

d) Pluto  

Explanation: Neptune takes ~165 years to orbit the Sun.

917. Assertion (A): The Universe is homogeneous and isotropic at large scales.  

Reason (R): Matter is evenly distributed when viewed across billions of light years.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: On large scales, the Universe appears uniform.

918. Which mission studied Saturn’s moon Enceladus and discovered water geysers?  

a) Cassini ✅  

b) Juno  

c) Voyager 2  

d) Dragonfly  

Explanation: Cassini detected geysers on Enceladus.

919. Which planet has the slowest rotation (longest day)?  

a) Venus ✅  

b) Mercury  

c) Mars  

d) Earth  

Explanation: Venus rotates once in ~243 Earth days.

920. Assertion (A): The Great Red Spot is shrinking.  

Reason (R): Changes in Jupiter’s atmosphere are reducing its size.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Observations show the Great Red Spot is shrinking.

921. Which mission studied Pluto and the Kuiper Belt?  

a) New Horizons ✅  

b) Voyager 2  

c) Cassini  

d) Dawn  

Explanation: New Horizons flew past Pluto in 2015 and continues in Kuiper Belt.

922. Which planet has the most moons?  

a) Saturn ✅  

b) Jupiter  

c) Uranus  

d) Neptune  

Explanation: Saturn has 145 confirmed moons (as of 2025).

923. Assertion (A): The Universe is expanding at an accelerating rate.  

Reason (R): Dark energy drives the acceleration.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Dark energy causes accelerated expansion.

924. Which mission studied asteroid Vesta and dwarf planet Ceres?  

a) Dawn ✅  

b) Rosetta  

c) Cassini  

d) Juno  

Explanation: Dawn orbited Vesta and Ceres.

925. Which planet has the shortest orbital period?  

a) Mercury ✅  

b) Venus  

c) Earth  

d) Mars  

Explanation: Mercury completes an orbit in 88 Earth days.

926. Assertion (A): The Cosmic Microwave Background is uniform.  

Reason (R): It represents radiation from the early Universe.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: CMB is relic radiation from ~380,000 years after Big Bang.

927. Which mission studied comet 67P/Churyumov–Gerasimenko?  

a) Rosetta ✅  

b) Dawn  

c) Voyager 2  

d) Cassini  

Explanation: ESA’s Rosetta orbited comet 67P.

928. Which planet has the highest escape velocity?  

a) Jupiter ✅  

b) Saturn  

c) Neptune  

d) Earth  

Explanation: Jupiter’s escape velocity is ~59.5 km/s.

929. Assertion (A): Uranus and Neptune are called ice giants.  

Reason (R): They contain large amounts of water, ammonia, and methane.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Ice giants have icy mantles of water, ammonia, and methane.

930. Which telescope discovered exoplanets by transit method?  

a) Kepler ✅  

b) Hubble  

c) James Webb  

d) Spitzer  

Explanation: Kepler discovered thousands of exoplanets using transit method.

931. Assertion (A): Venus rotates in retrograde motion.  

Reason (R): Its rotation direction is opposite to most planets.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Venus rotates west to east, opposite to Earth.

932. Which planet has the strongest magnetic field?  

a) Jupiter ✅  

b) Saturn  

c) Earth  

d) Neptune  

Explanation: Jupiter’s magnetic field is ~20,000 times stronger than Earth’s.

933. Which mission studied Jupiter’s atmosphere and magnetosphere since 2016?  

a) Juno ✅  

b) Cassini  

c) Voyager 2  

d) Dragonfly  

Explanation: Juno is dedicated to Jupiter’s atmosphere and magnetic field.

934. Assertion (A): Uranus and Neptune are called ice giants.  

Reason (R): They contain large amounts of water, ammonia, and methane.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Ice giants have icy mantles of water, ammonia, and methane.

935. Which mission studied Saturn’s moon Titan with radar?  

a) Cassini ✅  

b) Dragonfly  

c) Perseverance  

d) MAVEN  

Explanation: Cassini mapped Titan’s surface with radar.

936. Which planet has the highest orbital eccentricity among major planets?  

a) Mercury ✅  

b) Venus  

c) Earth  

d) Mars  

Explanation: Mercury’s eccentricity is ~0.206.

937. Assertion (A): The Universe is expanding at an accelerating rate.  

Reason (R): Dark energy drives the acceleration.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Dark energy causes accelerated expansion.

938. Which mission studied Pluto and Kuiper Belt objects?  

a) New Horizons ✅  

b) Voyager 2  

c) Cassini  

d) Dawn  

Explanation: New Horizons flew past Pluto in 2015 and continues in Kuiper Belt.

939. Which planet has the shortest day (fastest rotation)?  

a) Jupiter ✅  

b) Saturn  

c) Neptune  

d) Earth  

Explanation: Jupiter rotates once in ~9.9 hours.

940. Assertion (A): Saturn’s rings are very thin compared to their width.  

Reason (R): Ring particles are spread out in a flat plane.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Saturn’s rings are less than 1 km thick.

941. Which mission studied asteroid Bennu and returned samples to Earth?  

a) OSIRIS-REx ✅  

b) Hayabusa2  

c) Dawn  

d) Rosetta  

Explanation: OSIRIS-REx delivered Bennu samples in 2023.

942. Which mission studied comet 67P/Churyumov–Gerasimenko?  

a) Rosetta ✅  

b) Dawn  

c) Voyager 2  

d) Cassini  

Explanation: ESA’s Rosetta orbited comet 67P.

943. Assertion (A): Mars has seasons like Earth.  

Reason (R): Mars has a similar axial tilt to Earth.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Mars’s tilt (~25°) causes seasons.

944. Which planet has the most moons as of 2025?  

a) Saturn ✅  

b) Jupiter  

c) Uranus  

d) Neptune  

Explanation: Saturn has 145 confirmed moons.

945. Which mission studied Mercury before BepiColombo?  

a) MESSENGER ✅  

b) Voyager 2  

c) Dawn  

d) Cassini  

Explanation: MESSENGER orbited Mercury from 2011–2015.

946. Assertion (A): The Milky Way contains a supermassive black hole at its center.  

Reason (R): Sagittarius A* is located in the galactic core.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Sagittarius A* is a supermassive black hole.

947. Which mission studied Saturn’s rings until 2017?  

a) Cassini ✅  

b) Juno  

c) Voyager 2  

d) Dragonfly  

Explanation: Cassini orbited Saturn for 13 years.

948. Which planet has the slowest rotation (longest day)?  

a) Venus ✅  

b) Mercury  

c) Mars  

d) Earth  

Explanation: Venus rotates once in ~243 Earth days.

949. Assertion (A): The Universe contains billions of galaxies.  

Reason (R): Each galaxy contains billions of stars.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Billions of galaxies exist, each with billions of stars.

950. Which mission is planned to explore Jupiter’s moon Europa?  

a) Europa Clipper ✅  

b) Juno  

c) Cassini  

d) Voyager 1  

Explanation: Europa Clipper will study Europa’s ocean and habitability.

951. Assertion (A): The Universe may end in a Big Freeze.  

Reason (R): Expansion will continue until stars burn out and galaxies fade.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Big Freeze is the most likely fate of the Universe.

952. Which possible fate of the Universe involves collapse back into a singularity?  

a) Big Crunch ✅  

b) Big Freeze  

c) Big Rip  

d) Steady State  

Explanation: Big Crunch means the Universe contracts into a singularity.

953. Which possible fate of the Universe involves galaxies tearing apart due to dark energy?  

a) Big Rip ✅  

b) Big Freeze  

c) Big Crunch  

d) Steady State  

Explanation: Big Rip suggests accelerated expansion tears galaxies apart.

954. Assertion (A): Dark matter cannot be directly observed.  

Reason (R): It does not emit or absorb light.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Dark matter is detected only through gravitational effects.

955. Which evidence supports the existence of dark energy?  

a) Accelerating expansion of the Universe ✅  

b) Cosmic Microwave Background  

c) Planetary motion  

d) Solar wind  

Explanation: Accelerating expansion indicates dark energy.

956. Assertion (A): The Hubble constant measures the rate of expansion of the Universe.  

Reason (R): It relates galaxy velocity to distance.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Hubble’s Law shows velocity increases with distance.

957. Which telescope discovered thousands of exoplanets using transit method?  

a) Kepler ✅  

b) Hubble  

c) James Webb  

d) Spitzer  

Explanation: Kepler detected exoplanets by observing dips in starlight.

958. Assertion (A): The observable Universe is limited.  

Reason (R): Light speed restricts how far we can see.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: The observable Universe is bounded by light speed.

959. Which mission is India’s first solar observatory at L1 point?  

a) Aditya-L1 ✅  

b) Chandrayaan-3  

c) Mangalyaan  

d) Shukrayaan  

Explanation: Aditya-L1 studies the Sun from L1.

960. Assertion (A): The Milky Way and Andromeda will eventually collide.  

Reason (R): Gravitational attraction is pulling them together.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Milky Way and Andromeda will merge in ~4 billion years.

961. Which mission studies the Sun’s corona by flying close to it?  

a) Parker Solar Probe ✅  

b) Aditya-L1  

c) Hubble  

d) Dragonfly  

Explanation: Parker Solar Probe dives into the Sun’s corona.

962. Assertion (A): Uranus is the coldest planet in the Solar System.  

Reason (R): Uranus emits very little internal heat.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Uranus has minimal internal heat compared to other giants.

963. Which mission studied Saturn’s moon Enceladus and discovered water geysers?  

a) Cassini ✅  

b) Juno  

c) Voyager 2  

d) Dragonfly  

Explanation: Cassini detected geysers on Enceladus.

964. Assertion (A): The Universe contains billions of galaxies.  

Reason (R): Each galaxy contains billions of stars.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Billions of galaxies exist, each with billions of stars.

965. Which mission studied asteroid Vesta and dwarf planet Ceres?  

a) Dawn ✅  

b) Rosetta  

c) Cassini  

d) Juno  

Explanation: Dawn orbited Vesta and Ceres.

966. Assertion (A): The Great Red Spot is shrinking.  

Reason (R): Changes in Jupiter’s atmosphere are reducing its size.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Observations show the Great Red Spot is shrinking.

967. Which telescope observes the Universe in infrared wavelengths?  

a) James Webb Space Telescope ✅  

b) Hubble  

c) Chandra  

d) Spitzer  

Explanation: JWST specializes in infrared astronomy.

968. Assertion (A): Pluto is classified as a dwarf planet.  

Reason (R): It does not clear its orbit of other debris.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Pluto fails the “clearing orbit” criterion.

969. Which mission studied comet 67P/Churyumov–Gerasimenko?  

a) Rosetta ✅  

b) Dawn  

c) Voyager 2  

d) Cassini  

Explanation: ESA’s Rosetta orbited comet 67P.

970. Assertion (A): The Universe is homogeneous and isotropic at large scales.  

Reason (R): Matter is evenly distributed when viewed across billions of light years.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: On large scales, the Universe appears uniform.

971. Assertion (A): Mercury experiences extreme temperature variations.  

Reason (R): It has no significant atmosphere to retain heat.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Mercury’s thin atmosphere causes drastic day-night temperature swings.

972. Which planet has the highest surface pressure?  

a) Venus ✅  

b) Earth  

c) Mars  

d) Jupiter  

Explanation: Venus’s atmosphere has ~92 times Earth’s surface pressure.

973. Which mission studied Saturn’s moon Titan with radar mapping?  

a) Cassini ✅  

b) Dragonfly  

c) Perseverance  

d) MAVEN  

Explanation: Cassini mapped Titan’s surface with radar.

974. Assertion (A): Neptune appears blue.  

Reason (R): Methane in its atmosphere absorbs red light.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Methane absorbs red light, giving Neptune its blue color.

975. Which mission studied Pluto and Kuiper Belt objects?  

a) New Horizons ✅  

b) Voyager 2  

c) Cassini  

d) Dawn  

Explanation: New Horizons flew past Pluto in 2015 and continues in Kuiper Belt.

976. Assertion (A): Jupiter has the shortest day among planets.  

Reason (R): It rotates once in ~9.9 hours.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Jupiter’s rapid rotation gives it the shortest day.

977. Which planet has the largest volcano in the Solar System?  

a) Mars ✅  

b) Earth  

c) Venus  

d) Mercury  

Explanation: Olympus Mons on Mars is the largest volcano.

978. Assertion (A): Saturn’s rings are composed of ice and rock particles.  

Reason (R): They reflect sunlight strongly.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Ice-rich particles make Saturn’s rings bright.

979. Which mission studied asteroid Bennu and returned samples to Earth?  

a) OSIRIS-REx ✅  

b) Hayabusa2  

c) Dawn  

d) Rosetta  

Explanation: OSIRIS-REx delivered Bennu samples in 2023.

980. Assertion (A): Uranus rotates on its side.  

Reason (R): Its axial tilt is ~98°.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Uranus’s tilt makes it rotate almost horizontally.

981. Which mission studied comet 67P/Churyumov–Gerasimenko?  

a) Rosetta ✅  

b) Dawn  

c) Voyager 2  

d) Cassini  

Explanation: ESA’s Rosetta orbited comet 67P.

982. Assertion (A): Venus is hotter than Mercury.  

Reason (R): Venus’s thick CO₂ atmosphere causes greenhouse effect.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Venus’s greenhouse effect makes it hotter than Mercury.

983. Which planet has the highest escape velocity?  

a) Jupiter ✅  

b) Saturn  

c) Neptune  

d) Earth  

Explanation: Jupiter’s escape velocity is ~59.5 km/s.

984. Assertion (A): The Milky Way is part of the Local Group.  

Reason (R): It is gravitationally bound with Andromeda and Triangulum galaxies.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: The Local Group includes Milky Way, Andromeda, and Triangulum.

985. Which mission studied Saturn’s rings until 2017?  

a) Cassini ✅  

b) Juno  

c) Voyager 2  

d) Dragonfly  

Explanation: Cassini orbited Saturn for 13 years.

986. Assertion (A): Mars has polar ice caps.  

Reason (R): They are composed of water ice and carbon dioxide ice.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Mars’s polar caps contain water and CO₂ ice.

987. Which telescope observes the Universe in infrared wavelengths?  

a) James Webb Space Telescope ✅  

b) Hubble  

c) Chandra  

d) Spitzer  

Explanation: JWST specializes in infrared astronomy.

988. Assertion (A): The Universe is homogeneous and isotropic at large scales.  

Reason (R): Matter is evenly distributed when viewed across billions of light years.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: On large scales, the Universe appears uniform.

989. Which mission studied asteroid Vesta and dwarf planet Ceres?  

a) Dawn ✅  

b) Rosetta  

c) Cassini  

d) Juno  

Explanation: Dawn orbited Vesta and Ceres.

990. Assertion (A): The observable Universe is limited.  

Reason (R): Light speed restricts how far we can see.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: The observable Universe is bounded by light speed.

991. Assertion (A): Mercury has the shortest orbital period.  

Reason (R): It is the closest planet to the Sun.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Mercury completes an orbit in 88 Earth days.

992. Which planet has the thickest atmosphere among terrestrial planets?  

a) Venus ✅  

b) Earth  

c) Mars  

d) Mercury  

Explanation: Venus’s atmosphere is ~92 times Earth’s pressure.

993. Assertion (A): The Milky Way contains a supermassive black hole at its center.  

Reason (R): Sagittarius A* is located in the galactic core.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Sagittarius A* is a supermassive black hole.

994. Which mission studied Saturn’s moon Enceladus and discovered water geysers?  

a) Cassini ✅  

b) Juno  

c) Voyager 2  

d) Dragonfly  

Explanation: Cassini detected geysers on Enceladus.

995. Assertion (A): The Universe is expanding at an accelerating rate.  

Reason (R): Dark energy drives the acceleration.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Dark energy causes accelerated expansion.

996. Which mission studied asteroid Vesta and dwarf planet Ceres?  

a) Dawn ✅  

b) Rosetta  

c) Cassini  

d) Juno  

Explanation: Dawn orbited Vesta and Ceres.

997. Assertion (A): Uranus rotates on its side.  

Reason (R): Its axial tilt is ~98°.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Uranus’s tilt makes it rotate almost horizontally.

998. Which telescope observes the Universe in infrared wavelengths?  

a) James Webb Space Telescope ✅  

b) Hubble  

c) Chandra  

d) Spitzer  

Explanation: JWST specializes in infrared astronomy.

999. Assertion (A): Pluto is classified as a dwarf planet.  

Reason (R): It does not clear its orbit of other debris.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Pluto fails the “clearing orbit” criterion.

1000. Which mission studied comet 67P/Churyumov–Gerasimenko?  

a) Rosetta ✅  

b) Dawn  

c) Voyager 2  

d) Cassini  

Explanation: ESA’s Rosetta orbited comet 67P.

1001. Assertion (A): Mars has polar ice caps.  

Reason (R): They are composed of water ice and carbon dioxide ice.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Mars’s polar caps contain water and CO₂ ice.

1002. Which planet has the most moons as of 2025?  

a) Saturn ✅  

b) Jupiter  

c) Uranus  

d) Neptune  

Explanation: Saturn has 145 confirmed moons.

1003. Assertion (A): The Great Red Spot is shrinking.  

Reason (R): Changes in Jupiter’s atmosphere are reducing its size.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Observations show the Great Red Spot is shrinking.

1004. Which mission studied Pluto and Kuiper Belt objects?  

a) New Horizons ✅  

b) Voyager 2  

c) Cassini  

d) Dawn  

Explanation: New Horizons flew past Pluto in 2015 and continues in Kuiper Belt.

1005. Assertion (A): The observable Universe is limited.  

Reason (R): Light speed restricts how far we can see.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: The observable Universe is bounded by light speed.

1006. Which mission studied Saturn’s rings until 2017?  

a) Cassini ✅  

b) Juno  

c) Voyager 2  

d) Dragonfly  

Explanation: Cassini orbited Saturn for 13 years.

1007. Assertion (A): Venus is hotter than Mercury.  

Reason (R): Venus’s thick CO₂ atmosphere causes greenhouse effect.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Venus’s greenhouse effect makes it hotter than Mercury.

1008. Which planet has the highest escape velocity?  

a) Jupiter ✅  

b) Saturn  

c) Neptune  

d) Earth  

Explanation: Jupiter’s escape velocity is ~59.5 km/s.

1009. Assertion (A): The Milky Way is part of the Local Group.  

Reason (R): It is gravitationally bound with Andromeda and Triangulum galaxies.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: The Local Group includes Milky Way, Andromeda, and Triangulum.

1010. Which mission is planned to explore Jupiter’s moon Europa?  

a) Europa Clipper ✅  

b) Juno  

c) Cassini  

d) Voyager 1  

Explanation: Europa Clipper will study Europa’s ocean and habitability.

1011. Match the following missions with their targets:  

A) Juno 1) Jupiter  

B) Dawn 2) Vesta & Ceres  

C) Rosetta 3) Comet 67P  

D) New Horizons 4) Pluto  

a) A-1, B-2, C-3, D-4 ✅  

b) A-2, B-1, C-4, D-3  

c) A-3, B-4, C-1, D-2  

d) A-4, B-3, C-2, D-1  

Explanation: Each mission is matched to its primary target.

1012. Assertion (A): Venus is hotter than Mercury.  

Reason (R): Venus’s thick CO₂ atmosphere traps heat.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Greenhouse effect makes Venus hotter.

1013. Data Interpretation:  

Planetary Day Lengths (hours):  

- Jupiter: 9.9  

- Saturn: 10.7  

- Neptune: 16.1  

- Earth: 24  

Q: Which planet has the shortest day?  

a) Jupiter ✅  

b) Saturn  

c) Neptune  

d) Earth  

Explanation: Jupiter rotates fastest.

1014. Assertion (A): Uranus rotates on its side.  

Reason (R): Its axial tilt is ~98°.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Uranus’s tilt makes it unique.

1015. Case Study:  

A spacecraft detects water vapor plumes erupting from a moon’s icy surface.  

Q: Which moon is most likely being studied?  

a) Enceladus ✅  

b) Titan  

c) Europa  

d) Ganymede  

Explanation: Enceladus has geysers.

1016. Assertion (A): The Universe is expanding at an accelerating rate.  

Reason (R): Dark energy drives the acceleration.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Dark energy causes acceleration.

1017. Match the following telescopes with their specialties:  

A) Hubble 1) Visible & UV  

B) JWST 2) Infrared  

C) Chandra 3) X-rays  

D) Kepler 4) Exoplanets (transit method)  

a) A-1, B-2, C-3, D-4 ✅  

b) A-2, B-1, C-4, D-3  

c) A-3, B-4, C-1, D-2  

d) A-4, B-3, C-2, D-1  

Explanation: Each telescope has a distinct specialty.

1018. Assertion (A): Saturn’s rings are very thin compared to their width.  

Reason (R): Ring particles are spread out in a flat plane.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Rings are less than 1 km thick.

1019. Case Study:  

A mission is planned to send a rotorcraft to explore Titan’s surface.  

Q: Which mission is this?  

a) Dragonfly ✅  

b) Cassini  

c) Perseverance  

d) Voyager 2  

Explanation: Dragonfly will explore Titan.

1020. Assertion (A): The Milky Way and Andromeda will eventually collide.  

Reason (R): Gravitational attraction is pulling them together.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Collision expected in ~4 billion years.

1021. Match the following planets with their features:  

A) Mars 1) Olympus Mons  

B) Jupiter 2) Great Red Spot  

C) Saturn 3) Rings  

D) Neptune 4) Fastest winds  

a) A-1, B-2, C-3, D-4 ✅  

b) A-2, B-1, C-4, D-3  

c) A-3, B-4, C-2, D-1  

d) A-4, B-3, C-1, D-2  

Explanation: Each planet has a signature feature.

1022. Assertion (A): Pluto is classified as a dwarf planet.  

Reason (R): It does not clear its orbit of other debris.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Pluto fails the “clearing orbit” criterion.

1023. Case Study:  

A spacecraft dives into the Sun’s corona to study solar wind.  

Q: Which mission is this?  

a) Parker Solar Probe ✅  

b) Aditya-L1  

c) Hubble  

d) Cassini  

Explanation: Parker Solar Probe studies the corona.

1024. Assertion (A): The Universe contains billions of galaxies.  

Reason (R): Each galaxy contains billions of stars.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Billions of galaxies exist, each with billions of stars.

1025. Match the following moons with their planets:  

A) Titan 1) Saturn  

B) Europa 2) Jupiter  

C) Triton 3) Neptune  

D) Ganymede 4) Jupiter  

a) A-1, B-2, C-3, D-4 ✅  

b) A-2, B-1, C-4, D-3  

c) A-3, B-4, C-1, D-2  

d) A-4, B-3, C-2, D-1  

Explanation: Titan-Saturn, Europa-Jupiter, Triton-Neptune, Ganymede-Jupiter.

1026. Assertion (A): Mars has seasons like Earth.  

Reason (R): Mars has a similar axial tilt to Earth.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Mars’s tilt (~25°) causes seasons.

1027. Case Study:  

A mission returns samples from asteroid Bennu to Earth.  

Q: Which mission is this?  

a) OSIRIS-REx ✅  

b) Hayabusa2  

c) Dawn  

d) Rosetta  

Explanation: OSIRIS-REx delivered Bennu samples.

1028. Assertion (A): Uranus is the coldest planet in the Solar System.  

Reason (R): Uranus emits very little internal heat.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Uranus has minimal internal heat compared to other giants.

1029. Match the following dwarf planets with their locations:  

A) Ceres 1) Asteroid Belt  

B) Pluto 2) Kuiper Belt  

C) Haumea 3) Kuiper Belt  

D) Eris 4) Kuiper Belt  

a) A-1, B-2, C-3, D-4 ✅  

b) A-2, B-1, C-4, D-3  

c) A-3, B-4, C-1, D-2  

d) A-4, B-3, C-2, D-1  

Explanation: Ceres in Asteroid Belt; Pluto, Haumea, Eris in Kuiper Belt.

1030. Assertion (A): The observable Universe is limited.  

Reason (R): Light speed restricts how far we can see.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: The observable Universe is bounded by the finite speed of light.

1031. Assertion (A): The Milky Way is a barred spiral galaxy.  

Reason (R): It has a central bar-shaped structure with spiral arms.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: The Milky Way has a bar and spiral arms.

1032. Match the following missions with their discoveries:  

A) Cassini 1) Water geysers on Enceladus  

B) Juno 2) Jupiter’s magnetosphere  

C) Dawn 3) Vesta & Ceres exploration  

D) Rosetta 4) Comet 67P study  

a) A-1, B-2, C-3, D-4 ✅  

b) A-2, B-1, C-4, D-3  

c) A-3, B-4, C-1, D-2  

d) A-4, B-3, C-2, D-1  

Explanation: Each mission is matched to its key discovery.

1033. Assertion (A): Venus rotates in retrograde motion.  

Reason (R): Its rotation direction is opposite to most planets.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Venus rotates west to east, opposite to Earth.

1034. Case Study:  

A spacecraft dives into the Sun’s corona to study solar wind.  

Q: Which mission is this?  

a) Parker Solar Probe ✅  

b) Aditya-L1  

c) Hubble  

d) Cassini  

Explanation: Parker Solar Probe studies the corona.

1035. Assertion (A): Uranus is the coldest planet in the Solar System.  

Reason (R): Uranus emits very little internal heat.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Uranus has minimal internal heat compared to other giants.

1036. Match the following telescopes with their specialties:  

A) Hubble 1) Visible & UV  

B) JWST 2) Infrared  

C) Chandra 3) X-rays  

D) Kepler 4) Exoplanets (transit method)  

a) A-1, B-2, C-3, D-4 ✅  

b) A-2, B-1, C-4, D-3  

c) A-3, B-4, C-1, D-2  

d) A-4, B-3, C-2, D-1  

Explanation: Each telescope has a distinct specialty.

1037. Assertion (A): Saturn’s rings are very thin compared to their width.  

Reason (R): Ring particles are spread out in a flat plane.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Rings are less than 1 km thick.

1038. Case Study:  

A mission returns samples from asteroid Bennu to Earth.  

Q: Which mission is this?  

a) OSIRIS-REx ✅  

b) Hayabusa2  

c) Dawn  

d) Rosetta  

Explanation: OSIRIS-REx delivered Bennu samples.

1039. Assertion (A): The Universe is expanding at an accelerating rate.  

Reason (R): Dark energy drives the acceleration.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Dark energy causes accelerated expansion.

1040. Match the following moons with their planets:  

A) Titan 1) Saturn  

B) Europa 2) Jupiter  

C) Triton 3) Neptune  

D) Ganymede 4) Jupiter  

a) A-1, B-2, C-3, D-4 ✅  

b) A-2, B-1, C-4, D-3  

c) A-3, B-4, C-1, D-2  

d) A-4, B-3, C-2, D-1  

Explanation: Titan-Saturn, Europa-Jupiter, Triton-Neptune, Ganymede-Jupiter.

1041. Assertion (A): Pluto is classified as a dwarf planet.  

Reason (R): It does not clear its orbit of other debris.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Pluto fails the “clearing orbit” criterion.

1042. Case Study:  

A spacecraft flies past Pluto and continues into the Kuiper Belt.  

Q: Which mission is this?  

a) New Horizons ✅  

b) Voyager 2  

c) Cassini  

d) Dawn  

Explanation: New Horizons continues exploring Kuiper Belt objects.

1043. Assertion (A): Mars has seasons like Earth.  

Reason (R): Mars has a similar axial tilt to Earth.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Mars’s tilt (~25°) causes seasons.

1044. Match the following dwarf planets with their locations:  

A) Ceres 1) Asteroid Belt  

B) Pluto 2) Kuiper Belt  

C) Haumea 3) Kuiper Belt  

D) Eris 4) Kuiper Belt  

a) A-1, B-2, C-3, D-4 ✅  

b) A-2, B-1, C-4, D-3  

c) A-3, B-4, C-1, D-2  

d) A-4, B-3, C-2, D-1  

Explanation: Ceres in Asteroid Belt; Pluto, Haumea, Eris in Kuiper Belt.

1045. Assertion (A): The Milky Way and Andromeda will eventually collide.  

Reason (R): Gravitational attraction is pulling them together.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Collision expected in ~4 billion years.

1046. Case Study:  

A mission studies Mars’s atmosphere from orbit.  

Q: Which mission is this?  

a) MAVEN ✅  

b) Perseverance  

c) Curiosity  

d) Phoenix  

Explanation: MAVEN studies Mars’s upper atmosphere.

1047. Assertion (A): The observable Universe is limited.  

Reason (R): Light speed restricts how far we can see.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: The observable Universe is bounded by light speed.

1048. Match the following planets with their features:  

A) Mars 1) Olympus Mons  

B) Jupiter 2) Great Red Spot  

C) Saturn 3) Rings  

D) Neptune 4) Fastest winds  

a) A-1, B-2, C-3, D-4 ✅  

b) A-2, B-1, C-4, D-3  

c) A-3, B-4, C-2, D-1  

d) A-4, B-3, C-1, D-2  

Explanation: Each planet has a signature feature.

1049. Assertion (A): The Universe contains billions of galaxies.  

Reason (R): Each galaxy contains billions of stars.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Billions of galaxies exist, each with billions of stars.

1050. Case Study:  

A mission is planned to explore Jupiter’s moon Europa for signs of habitability.  

Q: Which mission is this?  

a) Europa Clipper ✅  

b) Juno  

c) Cassini  

d) Voyager

1051. Assertion (A): Mercury has extreme temperature variations.  

Reason (R): It lacks a significant atmosphere to retain heat.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Mercury’s thin atmosphere causes drastic day-night swings.

1052. Match the following missions with their agencies:  

A) JUICE 1) ESA  

B) Juno 2) NASA  

C) BepiColombo 3) ESA–JAXA  

D) Aditya-L1 4) ISRO  

a) A-1, B-2, C-3, D-4 ✅  

b) A-2, B-1, C-4, D-3  

c) A-3, B-4, C-1, D-2  

d) A-4, B-3, C-2, D-1  

Explanation: JUICE–ESA, Juno–NASA, BepiColombo–ESA/JAXA, Aditya-L1–ISRO.

1053. Assertion (A): Venus rotates in retrograde motion.  

Reason (R): Its rotation direction is opposite to most planets.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Venus rotates west to east, opposite to Earth.

1054. Case Study:  

A spacecraft detects geysers of water vapor erupting from a moon’s icy crust.  

Q: Which moon is most likely being studied?  

a) Enceladus ✅  

b) Titan  

c) Europa  

d) Ganymede  

Explanation: Enceladus ejects water vapor plumes.

1055. Assertion (A): The Milky Way and Andromeda will eventually collide.  

Reason (R): Gravitational attraction is pulling them together.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Collision expected in ~4 billion years.

1056. Match the following telescopes with their discoveries:  

A) Hubble 1) Accelerating expansion of Universe  

B) Kepler 2) Thousands of exoplanets  

C) JWST 3) Infrared deep space images  

D) Chandra 4) X-ray sources in galaxies  

a) A-1, B-2, C-3, D-4 ✅  

b) A-2, B-1, C-4, D-3  

c) A-3, B-4, C-1, D-2  

d) A-4, B-3, C-2, D-1  

Explanation: Each telescope has unique contributions.

1057. Assertion (A): Uranus is the coldest planet in the Solar System.  

Reason (R): Uranus emits very little internal heat.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Uranus has minimal internal heat compared to other giants.

1058. Case Study:  

A mission is planned to send a rotorcraft to Titan’s surface.  

Q: Which mission is this?  

a) Dragonfly ✅  

b) Cassini  

c) Perseverance  

d) Voyager 2  

Explanation: Dragonfly will explore Titan.

1059. Assertion (A): Saturn’s rings are very thin compared to their width.  

Reason (R): Ring particles are spread out in a flat plane.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Rings are less than 1 km thick.

1060. Match the following planets with their features:  

A) Mars 1) Olympus Mons  

B) Jupiter 2) Great Red Spot  

C) Saturn 3) Rings  

D) Neptune 4) Fastest winds  

a) A-1, B-2, C-3, D-4 ✅  

b) A-2, B-1, C-4, D-3  

c) A-3, B-4, C-2, D-1  

d) A-4, B-3, C-1, D-2  

Explanation: Each planet has a signature feature.

1061. Assertion (A): Pluto is classified as a dwarf planet.  

Reason (R): It does not clear its orbit of other debris.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Pluto fails the “clearing orbit” criterion.

1062. Case Study:  

A spacecraft flies past Pluto and continues into the Kuiper Belt.  

Q: Which mission is this?  

a) New Horizons ✅  

b) Voyager 2  

c) Cassini  

d) Dawn  

Explanation: New Horizons continues exploring Kuiper Belt objects.

1063. Assertion (A): Mars has seasons like Earth.  

Reason (R): Mars has a similar axial tilt to Earth.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Mars’s tilt (~25°) causes seasons.

1064. Match the following dwarf planets with their locations:  

A) Ceres 1) Asteroid Belt  

B) Pluto 2) Kuiper Belt  

C) Haumea 3) Kuiper Belt  

D) Eris 4) Kuiper Belt  

a) A-1, B-2, C-3, D-4 ✅  

b) A-2, B-1, C-4, D-3  

c) A-3, B-4, C-1, D-2  

d) A-4, B-3, C-2, D-1  

Explanation: Ceres in Asteroid Belt; Pluto, Haumea, Eris in Kuiper Belt.

1065. Assertion (A): The Universe contains billions of galaxies.  

Reason (R): Each galaxy contains billions of stars.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Billions of galaxies exist, each with billions of stars.

1066. Case Study:  

A mission studies Mars’s atmosphere from orbit.  

Q: Which mission is this?  

a) MAVEN ✅  

b) Perseverance  

c) Curiosity  

d) Phoenix  

Explanation: MAVEN studies Mars’s upper atmosphere.

1067. Assertion (A): The observable Universe is limited.  

Reason (R): Light speed restricts how far we can see.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: The observable Universe is bounded by light speed.

1068. Match the following missions with their targets:  

A) Juno 1) Jupiter  

B) Dawn 2) Vesta & Ceres  

C) Rosetta 3) Comet 67P  

D) OSIRIS-REx 4) Asteroid Bennu  

a) A-1, B-2, C-3, D-4 ✅  

b) A-2, B-1, C-4, D-3  

c) A-3, B-4, C-1, D-2  

d) A-4, B-3, C-2, D-1  

Explanation: Each mission matched to its target.

1069. Assertion (A): The Milky Way is part of the Local Group.  

Reason (R): It is gravitationally bound with Andromeda and Triangulum galaxies.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: The Local Group includes Milky Way, Andromeda, and Triangulum.

1070. Case Study:  

A mission is planned to explore Jupiter’s moon Europa for signs of habitability.  

Q: Which mission is this?  

a) Europa Clipper ✅  

b) Juno  

c) Cassini  

d) Voyager 1  

Explanation: Europa Clipper will study Europa’s ocean and habitability.

1071. Assertion (A): The Milky Way is part of the Local Group.  

Reason (R): It is gravitationally bound with Andromeda and Triangulum galaxies.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: The Local Group includes Milky Way, Andromeda, and Triangulum.

1072. Match the following missions with their targets:  

A) Juno 1) Jupiter  

B) Dawn 2) Vesta & Ceres  

C) Rosetta 3) Comet 67P  

D) OSIRIS-REx 4) Asteroid Bennu  

a) A-1, B-2, C-3, D-4 ✅  

b) A-2, B-1, C-4, D-3  

c) A-3, B-4, C-1, D-2  

d) A-4, B-3, C-2, D-1  

Explanation: Each mission matched to its target.

1073. Assertion (A): The Universe is homogeneous and isotropic at large scales.  

Reason (R): Matter is evenly distributed when viewed across billions of light years.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: On large scales, the Universe appears uniform.

1074. Case Study:  

A spacecraft dives into the Sun’s corona to study solar wind.  

Q: Which mission is this?  

a) Parker Solar Probe ✅  

b) Aditya-L1  

c) Hubble  

d) Cassini  

Explanation: Parker Solar Probe studies the corona.

1075. Assertion (A): Uranus rotates on its side.  

Reason (R): Its axial tilt is ~98°.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Uranus’s tilt makes it unique.

1076. Match the following telescopes with their specialties:  

A) Hubble 1) Visible & UV  

B) JWST 2) Infrared  

C) Chandra 3) X-rays  

D) Kepler 4) Exoplanets (transit method)  

a) A-1, B-2, C-3, D-4 ✅  

b) A-2, B-1, C-4, D-3  

c) A-3, B-4, C-1, D-2  

d) A-4, B-3, C-2, D-1  

Explanation: Each telescope has a distinct specialty.

1077. Assertion (A): Saturn’s rings are very thin compared to their width.  

Reason (R): Ring particles are spread out in a flat plane.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Rings are less than 1 km thick.

1078. Case Study:  

A mission returns samples from asteroid Bennu to Earth.  

Q: Which mission is this?  

a) OSIRIS-REx ✅  

b) Hayabusa2  

c) Dawn  

d) Rosetta  

Explanation: OSIRIS-REx delivered Bennu samples.

1079. Assertion (A): The Universe is expanding at an accelerating rate.  

Reason (R): Dark energy drives the acceleration.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Dark energy causes accelerated expansion.

1080. Match the following moons with their planets:  

A) Titan 1) Saturn  

B) Europa 2) Jupiter  

C) Triton 3) Neptune  

D) Ganymede 4) Jupiter  

a) A-1, B-2, C-3, D-4 ✅  

b) A-2, B-1, C-4, D-3  

c) A-3, B-4, C-1, D-2  

d) A-4, B-3, C-2, D-1  

Explanation: Titan-Saturn, Europa-Jupiter, Triton-Neptune, Ganymede-Jupiter.

1081. Assertion (A): Pluto is classified as a dwarf planet.  

Reason (R): It does not clear its orbit of other debris.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Pluto fails the “clearing orbit” criterion.

1082. Case Study:  

A spacecraft flies past Pluto and continues into the Kuiper Belt.  

Q: Which mission is this?  

a) New Horizons ✅  

b) Voyager 2  

c) Cassini  

d) Dawn  

Explanation: New Horizons continues exploring Kuiper Belt objects.

1083. Assertion (A): Mars has seasons like Earth.  

Reason (R): Mars has a similar axial tilt to Earth.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Mars’s tilt (~25°) causes seasons.

1084. Match the following dwarf planets with their locations:  

A) Ceres 1) Asteroid Belt  

B) Pluto 2) Kuiper Belt  

C) Haumea 3) Kuiper Belt  

D) Eris 4) Kuiper Belt  

a) A-1, B-2, C-3, D-4 ✅  

b) A-2, B-1, C-4, D-3  

c) A-3, B-4, C-1, D-2  

d) A-4, B-3, C-2, D-1  

Explanation: Ceres in Asteroid Belt; Pluto, Haumea, Eris in Kuiper Belt.

1085. Assertion (A): The Milky Way contains a supermassive black hole at its center.  

Reason (R): Sagittarius A* is located in the galactic core.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Sagittarius A* is a supermassive black hole.

1086. Case Study:  

A mission studies Mars’s atmosphere from orbit.  

Q: Which mission is this?  

a) MAVEN ✅  

b) Perseverance  

c) Curiosity  

d) Phoenix  

Explanation: MAVEN studies Mars’s upper atmosphere.

1087. Assertion (A): The observable Universe is limited.  

Reason (R): Light speed restricts how far we can see.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: The observable Universe is bounded by light speed.

1088. Match the following planets with their features:  

A) Mars 1) Olympus Mons  

B) Jupiter 2) Great Red Spot  

C) Saturn 3) Rings  

D) Neptune 4) Fastest winds  

a) A-1, B-2, C-3, D-4 ✅  

b) A-2, B-1, C-4, D-3  

c) A-3, B-4, C-2, D-1  

d) A-4, B-3, C-1, D-2  

Explanation: Each planet has a signature feature.

1089. Assertion (A): The Universe contains billions of galaxies.  

Reason (R): Each galaxy contains billions of stars.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Billions of galaxies exist, each with billions

1091. Assertion (A): Mercury has the highest orbital eccentricity among major planets.  

Reason (R): Its orbit is highly elliptical compared to others.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Mercury’s eccentricity is ~0.206, the highest among major planets.

1092. Match the following missions with their launch years:  

A) Cassini 1) 1997  

B) Juno 2) 2011  

C) New Horizons 3) 2006  

D) Parker Solar Probe 4) 2018  

a) A-1, B-2, C-3, D-4 ✅  

b) A-2, B-1, C-4, D-3  

c) A-3, B-4, C-1, D-2  

d) A-4, B-3, C-2, D-1  

Explanation: Cassini (1997), Juno (2011), New Horizons (2006), Parker Solar Probe (2018).

1093. Assertion (A): Venus is hotter than Mercury.  

Reason (R): Venus’s thick CO₂ atmosphere traps heat.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Greenhouse effect makes Venus hotter.

1094. Case Study:  

A spacecraft orbits Mercury as part of a joint ESA–JAXA mission.  

Q: Which mission is this?  

a) BepiColombo ✅  

b) MESSENGER  

c) Voyager 2  

d) Dawn  

Explanation: BepiColombo is ESA–JAXA’s Mercury mission.

1095. Assertion (A): The Milky Way contains a supermassive black hole at its center.  

Reason (R): Sagittarius A* is located in the galactic core.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Sagittarius A* is a supermassive black hole.

1096. Match the following telescopes with their agencies:  

A) Hubble 1) NASA–ESA  

B) JWST 2) NASA–ESA–CSA  

C) Chandra 3) NASA  

D) Kepler 4) NASA  

a) A-1, B-2, C-3, D-4 ✅  

b) A-2, B-1, C-4, D-3  

c) A-3, B-4, C-1, D-2  

d) A-4, B-3, C-2, D-1  

Explanation: Hubble (NASA–ESA), JWST (NASA–ESA–CSA), Chandra (NASA), Kepler (NASA).

1097. Assertion (A): Uranus is the coldest planet in the Solar System.  

Reason (R): Uranus emits very little internal heat.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Uranus has minimal internal heat compared to other giants.

1098. Case Study:  

A mission studies Saturn’s moon Titan with radar mapping.  

Q: Which mission is this?  

a) Cassini ✅  

b) Dragonfly  

c) Perseverance  

d) MAVEN  

Explanation: Cassini mapped Titan’s surface with radar.

1099. Assertion (A): Saturn’s rings are very thin compared to their width.  

Reason (R): Ring particles are spread out in a flat plane.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Rings are less than 1 km thick.

1100. Match the following planets with their orbital periods:  

A) Mercury 1) 88 days  

B) Earth 2) 365 days  

C) Jupiter 3) 12 years  

D) Neptune 4) 165 years  

a) A-1, B-2, C-3, D-4 ✅  

b) A-2, B-1, C-4, D-3  

c) A-3, B-4, C-1, D-2  

d) A-4, B-3, C-2, D-1  

Explanation: Mercury–88 days, Earth–365 days, Jupiter–12 years, Neptune–165 years.

1101. Assertion (A): Pluto is classified as a dwarf planet.  

Reason (R): It does not clear its orbit of other debris.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Pluto fails the “clearing orbit” criterion.

1102. Case Study:  

A spacecraft flies past Pluto and continues into the Kuiper Belt.  

Q: Which mission is this?  

a) New Horizons ✅  

b) Voyager 2  

c) Cassini  

d) Dawn  

Explanation: New Horizons continues exploring Kuiper Belt objects.

1103. Assertion (A): Mars has seasons like Earth.  

Reason (R): Mars has a similar axial tilt to Earth.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Mars’s tilt (~25°) causes seasons.

1104. Match the following dwarf planets with their locations:  

A) Ceres 1) Asteroid Belt  

B) Pluto 2) Kuiper Belt  

C) Haumea 3) Kuiper Belt  

D) Eris 4) Kuiper Belt  

a) A-1, B-2, C-3, D-4 ✅  

b) A-2, B-1, C-4, D-3  

c) A-3, B-4, C-1, D-2  

d) A-4, B-3, C-2, D-1  

Explanation: Ceres in Asteroid Belt; Pluto, Haumea, Eris in Kuiper Belt.

1105. Assertion (A): The Universe contains billions of galaxies.  

Reason (R): Each galaxy contains billions of stars.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Billions of galaxies exist, each with billions of stars.

1106. Case Study:  

A mission studies Mars’s atmosphere from orbit.  

Q: Which mission is this?  

a) MAVEN ✅  

b) Perseverance  

c) Curiosity  

d) Phoenix  

Explanation: MAVEN studies Mars’s upper atmosphere.

1107. Assertion (A): The observable Universe is limited.  

Reason (R): Light speed restricts how far we can see.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: The observable Universe is bounded by light speed.

1108. Match the following missions with their discoveries:  

A) Cassini 1) Water geysers on Enceladus  

B) Juno 2) Jupiter’s magnetosphere  

C) Dawn 3) Vesta & Ceres exploration  

D) Rosetta 4) Comet 67P study  

a) A-1, B-2, C-3, D-4 ✅  

b) A-2, B-1, C-4, D-3  

c) A-3, B-4, C-1, D-2  

d) A-4, B-3, C-2, D-1  

Explanation: Each mission is matched to its key discovery.

1109. Assertion (A): The Milky Way and Andromeda will eventually collide.  

Reason (R): Gravitational attraction is pulling them together.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Collision expected in ~4 billion years.

1110. Case Study:  

A mission is planned to explore Jupiter’s moon Europa for signs of habitability.  

Q: Which mission is this?  

a) Europa Clipper ✅  

b) Juno  

c) Cassini  

d) Voyager 1  

Explanation: Europa Clipper will study Europa’s ocean and habitability.

1111. Assertion (A): Mercury has extreme temperature variations.  

Reason (R): It lacks a significant atmosphere to retain heat.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Mercury’s thin atmosphere causes drastic day-night swings.

1112. Match the following missions with their agencies:  

A) JUICE 1) ESA  

B) Juno 2) NASA  

C) BepiColombo 3) ESA–JAXA  

D) Aditya-L1 4) ISRO  

a) A-1, B-2, C-3, D-4 ✅  

b) A-2, B-1, C-4, D-3  

c) A-3, B-4, C-1, D-2  

d) A-4, B-3, C-2, D-1  

Explanation: JUICE–ESA, Juno–NASA, BepiColombo–ESA/JAXA, Aditya-L1–ISRO.

1113. Assertion (A): Venus rotates in retrograde motion.  

Reason (R): Its rotation direction is opposite to most planets.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Venus rotates west to east, opposite to Earth.

1114. Case Study:  

A spacecraft detects geysers of water vapor erupting from a moon’s icy crust.  

Q: Which moon is most likely being studied?  

a) Enceladus ✅  

b) Titan  

c) Europa  

d) Ganymede  

Explanation: Enceladus ejects water vapor plumes.

1115. Assertion (A): The Milky Way and Andromeda will eventually collide.  

Reason (R): Gravitational attraction is pulling them together.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Collision expected in ~4 billion years.

1116. Match the following telescopes with their discoveries:  

A) Hubble 1) Accelerating expansion of Universe  

B) Kepler 2) Thousands of exoplanets  

C) JWST 3) Infrared deep space images  

D) Chandra 4) X-ray sources in galaxies  

a) A-1, B-2, C-3, D-4 ✅  

b) A-2, B-1, C-4, D-3  

c) A-3, B-4, C-1, D-2  

d) A-4, B-3, C-2, D-1  

Explanation: Each telescope has unique contributions.

1117. Assertion (A): Uranus is the coldest planet in the Solar System.  

Reason (R): Uranus emits very little internal heat.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Uranus has minimal internal heat compared to other giants.

1118. Case Study:  

A mission is planned to send a rotorcraft to Titan’s surface.  

Q: Which mission is this?  

a) Dragonfly ✅  

b) Cassini  

c) Perseverance  

d) Voyager 2  

Explanation: Dragonfly will explore Titan.

1119. Assertion (A): Saturn’s rings are very thin compared to their width.  

Reason (R): Ring particles are spread out in a flat plane.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Rings are less than 1 km thick.

1120. Match the following planets with their orbital periods:  

A) Mercury 1) 88 days  

B) Earth 2) 365 days  

C) Jupiter 3) 12 years  

D) Neptune 4) 165 years  

a) A-1, B-2, C-3, D-4 ✅  

b) A-2, B-1, C-4, D-3  

c) A-3, B-4, C-1, D-2  

d) A-4, B-3, C-2, D-1  

Explanation: Mercury–88 days, Earth–365 days, Jupiter–12 years, Neptune–165 years.

1121. Assertion (A): Pluto is classified as a dwarf planet.  

Reason (R): It does not clear its orbit of other debris.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Pluto fails the “clearing orbit” criterion.

1122. Case Study:  

A spacecraft flies past Pluto and continues into the Kuiper Belt.  

Q: Which mission is this?  

a) New Horizons ✅  

b) Voyager 2  

c) Cassini  

d) Dawn  

Explanation: New Horizons continues exploring Kuiper Belt objects.

1123. Assertion (A): Mars has seasons like Earth.  

Reason (R): Mars has a similar axial tilt to Earth.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Mars’s tilt (~25°) causes seasons.

1124. Match the following dwarf planets with their locations:  

A) Ceres 1) Asteroid Belt  

B) Pluto 2) Kuiper Belt  

C) Haumea 3) Kuiper Belt  

D) Eris 4) Kuiper Belt  

a) A-1, B-2, C-3, D-4 ✅  

b) A-2, B-1, C-4, D-3  

c) A-3, B-4, C-1, D-2  

d) A-4, B-3, C-2, D-1  

Explanation: Ceres in Asteroid Belt; Pluto, Haumea, Eris in Kuiper Belt.

1125. Assertion (A): The Universe contains billions of galaxies.  

Reason (R): Each galaxy contains billions of stars.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Billions of galaxies exist, each with billions of stars.

1126. Case Study:  

A mission studies Mars’s atmosphere from orbit.  

Q: Which mission is this?  

a) MAVEN ✅  

b) Perseverance  

c) Curiosity  

d) Phoenix  

Explanation: MAVEN studies Mars’s upper atmosphere.

1127. Assertion (A): The observable Universe is limited.  

Reason (R): Light speed restricts how far we can see.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: The observable Universe is bounded by light speed.

1128. Match the following missions with their discoveries:  

A) Cassini 1) Water geysers on Enceladus  

B) Juno 2) Jupiter’s magnetosphere  

C) Dawn 3) Vesta & Ceres exploration  

D) Rosetta 4) Comet 67P study  

a) A-1, B-2, C-3, D-4 ✅  

b) A-2, B-1, C-4, D-3  

c) A-3, B-4, C-1, D-2  

d) A-4, B-3, C-2, D-1  

Explanation: Each mission is matched to its key discovery.

1129. Assertion (A): The Milky Way and Andromeda will eventually collide.  

Reason (R): Gravitational attraction is pulling them together.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Collision expected in ~4 billion years.

1130. Case Study:  

A spacecraft dives into the Sun’s corona to study solar wind.  

Q: Which mission is this?  

a) Parker Solar Probe ✅  

b) Aditya-L1  

c) Hubble  

d) Cassini  

Explanation: Parker Solar Probe studies the corona.

1131. Assertion (A): Uranus rotates on its side.  

Reason (R): Its axial tilt is ~98°.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Uranus’s tilt makes it unique.

1132. Match the following telescopes with their specialties:  

A) Hubble 1) Visible & UV  

B) JWST 2) Infrared  

C) Chandra 3) X-rays  

D) Kepler 4) Exoplanets (transit method)  

a) A-1, B-2, C-3, D-4 ✅  

b) A-2, B-1, C-4, D-3  

c) A-3, B-4, C-1, D-2  

d) A-4, B-3, C-2, D-1  

Explanation: Each telescope has a distinct specialty.

1133. Assertion (A): Saturn’s rings are very thin compared to their width.  

Reason (R): Ring particles are spread out in a flat plane.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Rings are less than 1 km thick.

1134. Case Study:  

A mission returns samples from asteroid Bennu to Earth.  

Q: Which mission is this?  

a) OSIRIS-REx ✅  

b) Hayabusa2  

c) Dawn  

d) Rosetta  

Explanation: OSIRIS-REx delivered Bennu samples.

1135. Assertion (A): The Universe is expanding at an accelerating rate.  

Reason (R): Dark energy drives the acceleration.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Dark energy causes accelerated expansion.

1136. Match the following moons with their planets:  

A) Titan 1) Saturn  

B) Europa 2) Jupiter  

C) Triton 3) Neptune  

D) Ganymede 4) Jupiter  

a) A-1, B-2, C-3, D-4 ✅  

b) A-2, B-1, C-4, D-3  

c) A-3, B-4, C-1, D-2  

d) A-4, B-3, C-2, D-1  

Explanation: Titan-Saturn, Europa-Jupiter, Triton-Neptune, Ganymede-Jupiter.

1137. Assertion (A): Pluto is classified as a dwarf planet.  

Reason (R): It does not clear its orbit of other debris.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Pluto fails the “clearing orbit” criterion.

1138. Case Study:  

A spacecraft flies past Pluto and continues into the Kuiper Belt.  

Q: Which mission is this?  

a) New Horizons ✅  

b) Voyager 2  

c) Cassini  

d) Dawn  

Explanation: New Horizons continues exploring Kuiper Belt objects.

1139. Assertion (A): Mars has seasons like Earth.  

Reason (R): Mars has a similar axial tilt to Earth.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Mars’s tilt (~25°) causes seasons.

1140. Match the following dwarf planets with their locations:  

A) Ceres 1) Asteroid Belt  

B) Pluto 2) Kuiper Belt  

C) Haumea 3) Kuiper Belt  

D) Eris 4) Kuiper Belt  

a) A-1, B-2, C-3, D-4 ✅  

b) A-2, B-1, C-4, D-3  

c) A-3, B-4, C-1, D-2  

d) A-4, B-3, C-2, D-1  

Explanation: Ceres in Asteroid Belt; Pluto, Haumea, Eris in Kuiper Belt.

1141. Assertion (A): The Milky Way contains a supermassive black hole at its center.  

Reason (R): Sagittarius A* is located in the galactic core.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Sagittarius A* is a supermassive black hole.

1142. Case Study:  

A mission studies Mars’s atmosphere from orbit.  

Q: Which mission is this?  

a) MAVEN ✅  

b) Perseverance  

c) Curiosity  

d) Phoenix  

Explanation: MAVEN studies Mars’s upper atmosphere.

1143. Assertion (A): The observable Universe is limited.  

Reason (R): Light speed restricts how far we can see.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: The observable Universe is bounded by light speed.

1144. Match the following missions with their discoveries:  

A) Cassini 1) Water geysers on Enceladus  

B) Juno 2) Jupiter’s magnetosphere  

C) Dawn 3) Vesta & Ceres exploration  

D) Rosetta 4) Comet 67P study  

a) A-1, B-2, C-3, D-4 ✅  

b) A-2, B-1, C-4, D-3  

c) A-3, B-4, C-1, D-2  

d) A-4, B-3, C-2, D-1  

Explanation: Each mission is matched to its key discovery.

1145. Assertion (A): The Milky Way and Andromeda will eventually collide.  

Reason (R): Gravitational attraction is pulling them together.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Collision expected in ~4 billion years.

1146. Case Study:  

A spacecraft dives into the Sun’s corona to study solar wind.  

Q: Which mission is this?  

a) Parker Solar Probe ✅  

b) Aditya-L1  

c) Hubble  

d) Cassini  

Explanation: Parker Solar Probe studies the corona.

1147. Assertion (A): Uranus rotates on its side.  

Reason (R): Its axial tilt is ~98°.  

a) Both A and R are true, R is the correct explanation ✅  

b) Both A and R are true, R is not the correct explanation  

c) A is true, R is false  

d) A is false, R is true  

Explanation: Uranus’s tilt makes it unique.

1148. Match the following telescopes with their specialties:  

A) Hubble 1) Visible & UV  

B) JWST 2) Infrared  

C) Chandra 3) X-rays  

D) Kepler 4) Exoplanets (transit method)  

a) A-1, B-2, C-3, D-4 ✅  

b) A-2, B-1, C-4, D-3  

c) A-3, B-4, C-1, D-2  

d) A-4, B-3, C-2, D-1  

Explanation: Each telescope has a distinct specialty.