UPSC Prelims 2009 · General Studies
Question 66: Science and Technology
Which one of the following planets has largest number of natural satellites or moons?
AnswerThe answer is (a).
At the time of the exam Jupiter had the largest number of known moons, with Saturn close behind; Mars has two and Venus has none. Both are gas giants with many moons, and the totals keep rising as new small moons are found. Jupiter's four big Galilean moons are Io, Europa, Ganymede and Callisto.
Why each option is right or wrong
- (a) Right at the time: Jupiter had the most known moons.
- (b) Mars has only two moons, Phobos and Deimos.
- (c) Saturn had a few fewer known moons then, though it leads now.
- (d) Venus has no natural satellites.
Worth knowing: New discoveries have put Saturn well ahead of Jupiter, with over two hundred known moons, so today the answer would be Saturn.
Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 2009, General Studies. UPSC's own paper isn't online; the words are from a published compilation. The paper on upsc.gov.in.