Our solar system consists of the Sun—a 4.6-billion-year-old star containing over 99% of the system’s mass—and all objects bound to it by gravity. It includes eight distinct planets, over 100 moons, dwarf planets like Pluto, plus asteroids and comets. The system is located in the Milky Way galaxy’s Orion Spur.
NDA & CDS 1 2026 Exam GK – Solar System
1. 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.
2. The largest planet in the Solar System is:
A) Saturn
B) Jupiter
C) Uranus
D) Neptune
Answer: B) Jupiter
Explanation: Jupiter is the biggest planet and has the strongest gravitational pull among all planets.
3. The Sun is mainly composed of:
A) Oxygen and Nitrogen
B) Hydrogen and Helium
C) Carbon and Oxygen
D) Nitrogen and Hydrogen
Answer: B) Hydrogen and Helium
Explanation: Sun is primarily made up of hydrogen (~74%) and helium (~24%).
4. Which planet has the maximum number of known moons?
A) Jupiter
B) Mars
C) Saturn
D) Neptune
Answer: C) Saturn
Explanation: Saturn currently holds the record for the highest number of confirmed moons.
5. The asteroid belt is located between which two planets?
A) Earth and Mars
B) Mars and Jupiter
C) Jupiter and Saturn
D) Venus and Earth
Answer: B) Mars and Jupiter
Explanation: The asteroid belt lies between Mars and Jupiter.
6. Which planet rotates from east to west (retrograde rotation)?
A) Earth
B) Mars
C) Venus
D) Jupiter
Answer: C) Venus
Explanation: Venus rotates in the opposite direction compared to most planets.
7. The International Astronomical Union (IAU) reclassified Pluto as a:
A) Planet
B) Asteroid
C) Dwarf Planet
D) Comet
Answer: C) Dwarf Planet
Explanation: In 2006, International Astronomical Union classified Pluto as a dwarf planet.
8. Which planet is known for its prominent ring system?
A) Jupiter
B) Uranus
C) Neptune
D) Saturn
Answer: D) Saturn
Explanation: Saturn is famous for its visible and extensive ring system.
9. The Earth completes one revolution around the Sun in:
A) 24 hours
B) 30 days
C) 365¼ days
D) 180 days
Answer: C) 365¼ days
Explanation: Earth takes about 365.25 days to orbit the Sun.
10. Which is the smallest planet in the Solar System?
A) Mars
B) Mercury
C) Venus
D) Pluto
Answer: B) Mercury
Explanation: Mercury is the smallest planet after Pluto was reclassified.
11. The Kuiper Belt lies beyond which planet?
A) Saturn
B) Uranus
C) Neptune
D) Jupiter
Answer: C) Neptune
Explanation: The Kuiper Belt extends beyond Neptune and contains icy bodies including Pluto.
12. Which planet is known as the “Morning Star” or “Evening Star”?
A) Mercury
B) Venus
C) Mars
D) Jupiter
Answer: B) Venus
Explanation: Venus is visible just before sunrise or after sunset.
13. Which is the hottest planet in the Solar System?
A) Mercury
B) Venus
C) Mars
D) Jupiter
Answer: B) Venus
Explanation: Due to its thick carbon dioxide atmosphere causing a strong greenhouse effect, Venus is the hottest planet.
14. The force that keeps planets in orbit around the Sun is:
A) Magnetic Force
B) Nuclear Force
C) Gravitational Force
D) Centrifugal Force
Answer: C) Gravitational Force
Explanation: The gravitational pull of the Sun keeps planets in orbit.
15. Which planet is called the “Blue Planet”?
A) Neptune
B) Uranus
C) Earth
D) Saturn
Answer: C) Earth
Explanation: Earth appears blue from space due to the abundance of water on its surface.
