1. The Milky Way galaxy is also known as:
a) Andromeda
b) Akash Ganga
c) Sombrero Galaxy
d) Whirlpool Galaxy
Answer: b) Akash Ganga
Explanation: In India, the Milky Way is called Akash Ganga because it resembles a flowing river in the sky.
2. Which is the nearest galaxy to the Milky Way?
a) Andromeda
b) Magellanic Clouds
c) Triangulum
d) Whirlpool
Answer: a) Andromeda
Explanation: The Andromeda Galaxy (M31) is the nearest major galaxy to the Milky Way, about 2.5 million light-years away.
3. The Sun belongs to which type of stars?
a) Neutron star
b) White dwarf
c) Yellow dwarf (Main-sequence star)
d) Red giant
Answer: c) Yellow dwarf (Main-sequence star)
Explanation: The Sun is a medium-sized G-type main-sequence star.
4. The average distance between the Earth and the Sun is called:
a) Light year
b) Astronomical Unit (AU)
c) Parsec
d) Solar constant
Answer: b) Astronomical Unit (AU)
Explanation: 1 AU = ~149.6 million km is the mean distance from Earth to Sun.
5. The Sun’s energy is produced by:
a) Nuclear fission
b) Nuclear fusion
c) Chemical reaction
d) Gravitational force
Answer: b) Nuclear fusion
Explanation: The Sun’s energy comes from fusion of hydrogen into helium in its core.
6. The brightest star in the night sky is:
a) Vega
b) Polaris
c) Sirius
d) Betelgeuse
Answer: c) Sirius
Explanation: Sirius (Dog Star) in Canis Major is the brightest star.
7. Which planet is known as the ‘Red Planet’?
a) Venus
b) Jupiter
c) Mars
d) Mercury
Answer: c) Mars
Explanation: Mars appears red due to iron oxide (rust) on its surface.
8. The largest planet in our solar system is:
a) Saturn
b) Jupiter
c) Neptune
d) Uranus
Answer: b) Jupiter
Explanation: Jupiter is the largest, with a diameter of ~142,984 km.
9. The smallest planet in our solar system is:
a) Pluto
b) Mercury
c) Mars
d) Venus
Answer: b) Mercury
Explanation: Mercury is the smallest planet, after Pluto was reclassified as a dwarf planet.
10. Which planet is known as Earth’s twin?
a) Mars
b) Venus
c) Neptune
d) Uranus
Answer: b) Venus
Explanation: Venus is called Earth’s twin because of similar size and mass.
11. Which planet is called the ‘Morning Star’ or ‘Evening Star’?
a) Venus
b) Mars
c) Mercury
d) Saturn
Answer: a) Venus
Explanation: Venus shines brightly and is visible near sunrise/sunset.
12. The asteroid belt lies between which two planets?
a) Earth & Mars
b) Mars & Jupiter
c) Jupiter & Saturn
d) Saturn & Uranus
Answer: b) Mars & Jupiter
Explanation: The Asteroid Belt separates inner and outer planets.
13. Which planet has the most moons?
a) Earth
b) Saturn
c) Jupiter
d) Neptune
Answer: b) Saturn
Explanation: Saturn (145 moons, as of 2025) has the most known natural satellites.
14. The largest moon of the Solar System is:
a) Titan
b) Ganymede
c) Europa
d) Triton
Answer: b) Ganymede
Explanation: Ganymede (moon of Jupiter) is the largest moon.
15. Which planet has a day longer than its year?
a) Mercury
b) Venus
c) Mars
d) Neptune
Answer: b) Venus
Explanation: Venus rotates very slowly—1 day = 243 Earth days, longer than its year (225 Earth days).
16. Which is the windiest planet in the Solar System?
a) Neptune
b) Jupiter
c) Saturn
d) Uranus
Answer: a) Neptune
Explanation: Neptune has winds blowing at 2,100 km/h, the fastest in the solar system.
17. Which is the densest planet in the Solar System?
a) Earth
b) Mercury
c) Saturn
d) Venus
Answer: a) Earth
Explanation: Earth has the highest density (~5.52 g/cm³) among planets.
18. The only planet known to support life is:
a) Earth
b) Venus
c) Mars
d) Europa
Answer: a) Earth
Explanation: Earth has liquid water, oxygen, and favorable atmosphere for life.
19. Which planet has a prominent ring system?
a) Jupiter
b) Saturn
c) Neptune
d) Uranus
Answer: b) Saturn
Explanation: Saturn’s rings are the most extensive and visible.
20. The planet with the highest surface temperature is:
a) Mercury
b) Venus
c) Mars
d) Jupiter
Answer: b) Venus
Explanation: Due to the greenhouse effect, Venus is hotter than Mercury.
21. The first artificial satellite launched by humans was:
a) Explorer 1
b) Sputnik 1
c) Aryabhata
d) Voyager 1
Answer: b) Sputnik 1
Explanation: USSR launched Sputnik 1 in 1957, the first artificial satellite.
22. The first Indian satellite was:
a) INSAT-1A
b) Bhaskara
c) Aryabhata
d) Rohini
Answer: c) Aryabhata
Explanation: India’s first satellite Aryabhata was launched in 1975.
23. Which planet rotates on its side (tilted axis ~98°)?
a) Neptune
b) Uranus
c) Saturn
d) Mars
Answer: b) Uranus
Explanation: Uranus rotates sideways, giving it extreme seasons.
24. The largest volcano in the Solar System is:
a) Mauna Kea (Earth)
b) Mount Everest (Earth)
c) Olympus Mons (Mars)
d) Rheasilvia (Vesta)
Answer: c) Olympus Mons (Mars)
Explanation: Olympus Mons is the largest volcano, 3 times taller than Everest.
25. A light year is a unit of:
a) Time
b) Distance
c) Speed
d) Energy
Answer: b) Distance
Explanation: A light year is the distance light travels in one year (~9.46 trillion km).
26. The planet known as the ‘Blue Planet’ is:
a) Neptune
b) Earth
c) Uranus
d) Saturn
Answer: b) Earth
Explanation: Earth is called the Blue Planet due to the presence of abundant water bodies.
27. Which planet has the shortest day (fastest rotation)?
a) Earth
b) Jupiter
c) Saturn
d) Neptune
Answer: b) Jupiter
Explanation: Jupiter rotates in just 9 hours 56 minutes, the shortest day of any planet.
28. Which is the hottest planet in the solar system?
a) Mercury
b) Venus
c) Mars
d) Neptune
Answer: b) Venus
Explanation: Venus has a thick CO₂ atmosphere causing extreme greenhouse effect, making it the hottest.
29. Which planet has the Great Red Spot?
a) Jupiter
b) Saturn
c) Neptune
d) Mars
Answer: a) Jupiter
Explanation: The Great Red Spot is a giant storm on Jupiter that has lasted for centuries.
30. Which planet is known as the “Ice Giant”?
a) Saturn
b) Uranus
c) Jupiter
d) Mercury
Answer: b) Uranus
Explanation: Uranus is called an Ice Giant because it contains water, ammonia, and methane ices.
31. Which is the second smallest planet in the solar system?
a) Mars
b) Venus
c) Mercury
d) Pluto
Answer: a) Mars
Explanation: Mars is the second smallest planet after Mercury.
32. Which planet has the highest number of active volcanoes?
a) Earth
b) Venus
c) Mars
d) Io (moon of Jupiter)
Answer: b) Venus
Explanation: Venus has thousands of volcanoes, with many still active.
33. The brightest planet as seen from Earth is:
a) Venus
b) Jupiter
c) Mars
d) Mercury
Answer: a) Venus
Explanation: Venus reflects most sunlight due to its thick clouds, making it the brightest.
34. Which planet has methane clouds giving it a bluish color?
a) Uranus and Neptune
b) Jupiter and Saturn
c) Mars and Venus
d) Earth and Mercury
Answer: a) Uranus and Neptune
Explanation: Methane in their atmospheres absorbs red light and reflects blue light.
35. Which is the coldest planet in the Solar System?
a) Neptune
b) Uranus
c) Saturn
d) Pluto
Answer: b) Uranus
Explanation: Uranus has the lowest average temperature (−224°C).
36. Which star is known as the Pole Star?
a) Vega
b) Polaris
c) Sirius
d) Betelgeuse
Answer: b) Polaris
Explanation: Polaris (Pole Star) lies almost directly above Earth’s North Pole, used in navigation.
37. Which galaxy is the Milky Way expected to collide with in the future?
a) Andromeda
b) Triangulum
c) Whirlpool
d) Sombrero
Answer: a) Andromeda
Explanation: The Milky Way and Andromeda galaxies are predicted to collide in about 4–5 billion years.
38. Which dwarf planet was once considered the ninth planet?
a) Eris
b) Haumea
c) Ceres
d) Pluto
Answer: d) Pluto
Explanation: Pluto was reclassified as a dwarf planet in 2006 by the IAU.
39. Which celestial body is known as the “Morning Star” in Indian tradition?
a) Mercury
b) Venus
c) Jupiter
d) Saturn
Answer: b) Venus
Explanation: Venus is called Shukra (Morning Star) in Indian tradition.
40. Which planet has hexagonal-shaped storms at its pole?
a) Jupiter
b) Saturn
c) Neptune
d) Uranus
Answer: b) Saturn
Explanation: Saturn’s north pole has a hexagon-shaped storm system observed by Voyager and Cassini.
41. Which planet is called the “Messenger of the Gods”?
a) Mercury
b) Venus
c) Mars
d) Jupiter
Answer: a) Mercury
Explanation: Named after Roman god Mercury, the swift messenger, due to its fast orbit.
42. Which planet takes the longest time to orbit the Sun?
a) Neptune
b) Uranus
c) Pluto
d) Saturn
Answer: a) Neptune
Explanation: Neptune takes about 165 Earth years to complete one orbit.
43. Which moon of Saturn has a thick atmosphere?
a) Titan
b) Enceladus
c) Rhea
d) Iapetus
Answer: a) Titan
Explanation: Titan has a dense nitrogen-rich atmosphere, even thicker than Earth’s.
44. Which planet is known for its “retrograde rotation”?
a) Mars
b) Venus
c) Earth
d) Jupiter
Answer: b) Venus
Explanation: Venus rotates backward (east to west) compared to most planets.
45. The Oort Cloud is believed to be the source of:
a) Asteroids
b) Comets
c) Meteors
d) Moons
Answer: b) Comets
Explanation: The Oort Cloud is a distant spherical shell of icy bodies, source of long-period comets.
46. Which comet is visible from Earth roughly every 76 years?
a) Encke’s Comet
b) Halley’s Comet
c) Hale–Bopp
d) Shoemaker–Levy 9
Answer: b) Halley’s Comet
Explanation: Halley’s Comet is the most famous periodic comet, last seen in 1986.
47. Meteors are popularly called:
a) Shooting stars
b) Asteroids
c) Comets
d) Satellites
Answer: a) Shooting stars
Explanation: Meteors burn upon entering Earth’s atmosphere, appearing as shooting stars.
48. The “Kuiper Belt” lies beyond which planet?
a) Neptune
b) Saturn
c) Uranus
d) Jupiter
Answer: a) Neptune
Explanation: The Kuiper Belt is a region beyond Neptune filled with icy objects and dwarf planets.
49. Which is the farthest known planet in the Solar System?
a) Uranus
b) Neptune
c) Pluto
d) Eris
Answer: b) Neptune
Explanation: Neptune is the farthest official planet; beyond it are dwarf planets.
50. The Sun completes one rotation about its axis in approximately:
a) 15 days
b) 25 days
c) 30 days
d) 45 days
Answer: b) 25 days
Explanation: The Sun takes about 25 Earth days to rotate once on its equator (slower at poles).
51. Which planet is known as the “Twin of Earth”?
a) Mars
b) Venus
c) Mercury
d) Saturn
Answer: b) Venus
Explanation: Venus is called Earth’s twin due to its similar size, mass, and composition.
52. The first artificial satellite launched by humans was:
a) Explorer 1
b) Sputnik 1
c) Aryabhata
d) Luna 2
Answer: b) Sputnik 1
Explanation: The Soviet Union launched Sputnik 1 in 1957, the first artificial satellite.
53. Which planet has the largest number of moons?
a) Saturn
b) Jupiter
c) Uranus
d) Neptune
Answer: a) Saturn
Explanation: Saturn has the highest number of confirmed moons (80+).
54. Which planet was discovered by telescope in 1846?
a) Uranus
b) Neptune
c) Pluto
d) Saturn
Answer: b) Neptune
Explanation: Neptune was the first planet discovered by mathematical prediction and telescope observation.
55. Which planet is tipped sideways with its axis tilted about 98°?
a) Neptune
b) Uranus
c) Venus
d) Mars
Answer: b) Uranus
Explanation: Uranus rotates on its side due to a 98° axial tilt.
56. Which is the second brightest object in the night sky after the Moon?
a) Jupiter
b) Venus
c) Mars
d) Saturn
Answer: b) Venus
Explanation: Venus is the second brightest object after the Moon, hence called the “Evening Star/Morning Star.”
57. Which is the nearest galaxy to the Milky Way?
a) Andromeda
b) Large Magellanic Cloud
c) Triangulum
d) Sombrero
Answer: b) Large Magellanic Cloud
Explanation: The Large Magellanic Cloud (LMC) is the closest galaxy to the Milky Way.
58. The Sun’s outermost layer is called:
a) Photosphere
b) Chromosphere
c) Corona
d) Convective zone
Answer: c) Corona
Explanation: The corona is the Sun’s outer atmosphere, visible during a solar eclipse.
59. Which planet is called the “Green Planet”?
a) Uranus
b) Earth
c) Neptune
d) Venus
Answer: a) Uranus
Explanation: Uranus appears greenish-blue due to methane absorption of red light.
60. Which is the brightest star in the night sky?
a) Vega
b) Sirius
c) Betelgeuse
d) Proxima Centauri
Answer: b) Sirius
Explanation: Sirius (Dog Star) in Canis Major is the brightest star visible from Earth.
61. Which Indian satellite was the first to be launched into space?
a) Bhaskara-I
b) Aryabhata
c) INSAT-1A
d) Rohini
Answer: b) Aryabhata
Explanation: India launched Aryabhata in 1975, its first satellite.
62. Which planet has the largest volcano, Olympus Mons?
a) Earth
b) Mars
c) Venus
d) Jupiter
Answer: b) Mars
Explanation: Olympus Mons on Mars is the largest volcano in the solar system.
63. The asteroid belt lies between:
a) Earth and Mars
b) Mars and Jupiter
c) Jupiter and Saturn
d) Saturn and Uranus
Answer: b) Mars and Jupiter
Explanation: The asteroid belt is located between Mars and Jupiter.
64. Which planet is known as the “Ringed Planet”?
a) Uranus
b) Jupiter
c) Saturn
d) Neptune
Answer: c) Saturn
Explanation: Saturn is famous for its prominent ring system made of ice and dust.
65. Which planet rotates in the shortest time?
a) Earth
b) Jupiter
c) Mars
d) Saturn
Answer: b) Jupiter
Explanation: Jupiter completes one rotation in 9 hours 56 minutes, the shortest among planets.
66. Which is the smallest planet in the Solar System?
a) Mercury
b) Mars
c) Pluto
d) Venus
Answer: a) Mercury
Explanation: Mercury is the smallest planet in size and mass after Pluto’s reclassification.
67. The Milky Way galaxy is shaped like a:
a) Ring
b) Spiral
c) Ellipse
d) Sphere
Answer: b) Spiral
Explanation: The Milky Way is a barred spiral galaxy.
68. Which planet is known as the “God of War”?
a) Mars
b) Jupiter
c) Venus
d) Mercury
Answer: a) Mars
Explanation: Mars is named after the Roman God of War because of its red color.
69. The Hubble Space Telescope is mainly used for:
a) Weather forecasting
b) Deep space observations
c) Satellite communication
d) GPS services
Answer: b) Deep space observations
Explanation: Hubble provides images and data about distant galaxies and stars.
70. Which planet is also known as the “Morning Star” and “Evening Star”?
a) Mercury
b) Venus
c) Mars
d) Saturn
Answer: b) Venus
Explanation: Venus is visible at dawn and dusk, hence called both Morning and Evening Star.
71. Which planet has winds reaching speeds of over 2000 km/h?
a) Jupiter
b) Saturn
c) Neptune
d) Uranus
Answer: c) Neptune
Explanation: Neptune has the fastest winds in the solar system (up to 2100 km/h).
72. Which star is the closest to Earth?
a) Sirius
b) Alpha Centauri
c) Proxima Centauri
d) Vega
Answer: c) Proxima Centauri
Explanation: Proxima Centauri is the nearest star to the Sun, about 4.24 light years away.
73. Which spacecraft first landed on the Moon?
a) Luna 2
b) Apollo 11
c) Surveyor 1
d) Chandrayaan-1
Answer: b) Apollo 11
Explanation: In 1969, Apollo 11 carried Neil Armstrong, the first human to land on the Moon.
74. Which planet has the largest storm system called the Great Dark Spot?
a) Jupiter
b) Neptune
c) Saturn
d) Uranus
Answer: b) Neptune
Explanation: Neptune has a massive storm system called the Great Dark Spot, similar to Jupiter’s Red Spot.
75. The Sun is classified as a:
a) Red Giant
b) Yellow Dwarf (G-type star)
c) White Dwarf
d) Neutron Star
Answer: b) Yellow Dwarf (G-type star)
Explanation: The Sun is a G2V main sequence star, commonly called a Yellow Dwarf.
76. Which planet has a day longer than its year?
a) Mercury
b) Venus
c) Mars
d) Jupiter
Answer: b) Venus
Explanation: Venus rotates so slowly that one day = 243 Earth days, longer than its year (225 days).
77. Which celestial body was reclassified as a dwarf planet in 2006?
a) Ceres
b) Pluto
c) Haumea
d) Eris
Answer: b) Pluto
Explanation: Pluto was reclassified by the International Astronomical Union (IAU) in 2006 as a dwarf planet.
78. The Great Red Spot is found on which planet?
a) Mars
b) Jupiter
c) Saturn
d) Uranus
Answer: b) Jupiter
Explanation: The Great Red Spot is a giant storm on Jupiter, persisting for centuries.
79. Which planet has a moon called Titan?
a) Jupiter
b) Saturn
c) Uranus
d) Neptune
Answer: b) Saturn
Explanation: Titan, Saturn’s largest moon, is bigger than Mercury and has a thick atmosphere.
80. Which is the coldest planet in the Solar System?
a) Uranus
b) Neptune
c) Saturn
d) Mars
Answer: a) Uranus
Explanation: Uranus has the lowest recorded atmospheric temperature (~ -224°C).
81. Which is the largest planet in the Solar System?
a) Saturn
b) Jupiter
c) Neptune
d) Earth
Answer: b) Jupiter
Explanation: Jupiter is the largest planet with a diameter of 142,984 km.
82. The distance traveled by light in one year is called:
a) Astronomical Unit
b) Light Year
c) Parsec
d) Cosmic Year
Answer: b) Light Year
Explanation: A light year is the distance light travels in one year (~9.46 trillion km).
83. The largest satellite in the Solar System is:
a) Titan
b) Ganymede
c) Europa
d) Callisto
Answer: b) Ganymede
Explanation: Jupiter’s moon Ganymede is the largest satellite, bigger than Mercury.
84. The first man to travel into space was:
a) Yuri Gagarin
b) Neil Armstrong
c) Alan Shepard
d) Rakesh Sharma
Answer: a) Yuri Gagarin
Explanation: Soviet cosmonaut Yuri Gagarin became the first human in space in 1961.
85. Which planet is known as the “Watery Planet”?
a) Earth
b) Mars
c) Venus
d) Neptune
Answer: a) Earth
Explanation: Earth is called the Watery Planet because 71% of its surface is covered by water.
86. The Chandrayaan-1 mission was launched in:
a) 2006
b) 2008
c) 2010
d) 2013
Answer: b) 2008
Explanation: Chandrayaan-1 was India’s first lunar mission, launched in 2008.
87. Which planet has the fastest revolution around the Sun?
a) Mercury
b) Venus
c) Mars
d) Earth
Answer: a) Mercury
Explanation: Mercury takes only 88 Earth days to complete one revolution.
88. Which planet is known as the “Windy Planet”?
a) Neptune
b) Saturn
c) Uranus
d) Jupiter
Answer: a) Neptune
Explanation: Neptune has the strongest winds in the solar system (up to 2100 km/h).
89. Which Indian astronaut went to space in 1984?
a) Kalpana Chawla
b) Rakesh Sharma
c) Sunita Williams
d) Vikram Sarabhai
Answer: b) Rakesh Sharma
Explanation: Rakesh Sharma was the first Indian to go into space in 1984 aboard Soyuz T-11.
90. The Moon is believed to have formed due to:
a) Capture theory
b) Fission theory
c) Giant impact theory
d) Gravitational theory
Answer: c) Giant impact theory
Explanation: The giant impact theory suggests the Moon formed after a Mars-sized body collided with Earth.
91. Which planet is often called the “Evening Star”?
a) Mars
b) Venus
c) Jupiter
d) Saturn
Answer: b) Venus
Explanation: Venus appears prominently in the evening sky, hence called the Evening Star.
92. The shape of the Earth is best described as:
a) Perfect sphere
b) Ellipsoid
c) Oblate spheroid
d) Round disc
Answer: c) Oblate spheroid
Explanation: Earth is an oblate spheroid – flattened at poles and bulging at the equator.
93. Which was the first Indian mission to Mars?
a) Mangalyaan (MOM)
b) Chandrayaan-1
c) Chandrayaan-2
d) INSAT-4A
Answer: a) Mangalyaan (MOM)
Explanation: Mangalyaan (Mars Orbiter Mission) was launched in 2013, India’s first mission to Mars.
94. Which galaxy is the Milky Way’s nearest major neighbor?
a) Triangulum Galaxy
b) Andromeda Galaxy
c) Sombrero Galaxy
d) Whirlpool Galaxy
Answer: b) Andromeda Galaxy
Explanation: Andromeda Galaxy (M31) is the nearest large spiral galaxy, about 2.5 million light years away.
95. Which is the densest planet in the Solar System?
a) Earth
b) Jupiter
c) Saturn
d) Venus
Answer: a) Earth
Explanation: Earth has the highest density (5.51 g/cm³) among all planets.
96. Which planet is also known as the “Morning Star”?
a) Venus
b) Mars
c) Mercury
d) Saturn
Answer: a) Venus
Explanation: Venus is visible in the east at dawn, hence called the Morning Star.
97. Which is the hottest planet in the Solar System?
a) Mercury
b) Venus
c) Mars
d) Jupiter
Answer: b) Venus
Explanation: Due to a thick carbon dioxide atmosphere, Venus has the hottest surface temperatures (~465°C).
98. Which spacecraft carried the first humans to the Moon?
a) Apollo 11
b) Sputnik 1
c) Luna 2
d) Voyager 1
Answer: a) Apollo 11
Explanation: Apollo 11 carried Neil Armstrong and Buzz Aldrin to the Moon in 1969.
99. Which planet has the slowest rotation?
a) Mercury
b) Venus
c) Neptune
d) Saturn
Answer: b) Venus
Explanation: Venus rotates extremely slowly – 1 rotation = 243 Earth days.
100. The center of our Solar System is:
a) Earth
b) Sun
c) Moon
d) Jupiter
Answer: b) Sun
Explanation: The Sun is the gravitational center of the Solar System, around which all planets revolve.