Home › PYQs › World Geography › All questions › 1998 · Asteroids
UPSC Prelims 1998 · World Geography · Earth in Space
Consider the following statements regarding asteroids: Which of these statements are correct?
- Asteroids are rocky debris of varying sizes orbiting the Sun.
- Most of the asteroids are small but some have a diameter as large as 1000 km.
- The orbit of asteroids lies between the orbits of Jupiter and Saturn.
- (a) 1, 2 and 3
- (b) 2 and 3
- (c) 1 and 2
- (d) 1 and 3
Show the answer and explanation
Answer: (c) 1 and 2
Rocky debris, some ~1,000 km; the belt is between Mars and Jupiter.
Statement by statement
1. ✓ CORRECT Asteroids are rocky bodies orbiting the Sun.
2. ✓ CORRECT Most are small; Ceres is ~940 km across.
3. ✗ WRONG The main belt lies between Mars and Jupiter, not Jupiter and Saturn.
The idea
The main asteroid belt contains bodies left from the early solar system that did not assemble into one planet. Jupiter’s gravity helped prevent that assembly. “Main belt” names their chief concentration, not the location of every asteroid.
Why the others are wrong
(a) Accepts Jupiter–Saturn.
(b) Accepts Jupiter–Saturn.
(d) Accepts Jupiter–Saturn.
The trap
Jupiter is right — the other neighbour is Mars.
Elimination technique
Locate Mars and Jupiter in the planetary order. The Jupiter–Saturn belt claim is false, so every option containing statement 3 is removed.
Also know
Near-Earth asteroids have orbits that bring them into Earth’s neighbourhood. Trojan asteroids share a planet’s orbit near stable gravitational positions. Ceres is a dwarf planet in the main belt; the Kuiper Belt lies beyond Neptune and contains many icy bodies, including Pluto.
🔒 Asteroid belt: Mars–Jupiter; Ceres = dwarf planet.
Solve this chapter interactively →All World Geography questions