Solar System and Evolution of Earth: UPSC Previous Year Questions (Geography)
16 previous year UPSC Prelims questions on the solar system and the evolution of Earth are listed here, from 1996 to 2025. UPSC asks about planets and their order, asteroids, the Moon’s rotation, the Sun-Earth distance and how little fresh water is available. The explanations give the physical reason for each answer.
Explanations state facts as of the year each question was asked; words like “recently” refer to that year.
Showing 11–16 of 16 questions
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UPSC 1998Geography · Solar System and Evolution of Earth
Q11. Match List-I with List-II and select the correct answer by using the codes given below the lists:
List-I (Special Characteristic)
List-II (Name of Planet)
A. Smallest planet of the solar system
1. Mercury
B. Largest planet of the solar system
2. Venus
C. Planet second from the Sun in the solar system
3. Jupiter
D. Planet nearest to the Sun
4. Pluto
5. Saturn
Explanation
A is correctly matched with 4: Pluto was considered the smallest planet in the solar system. It was reclassified as a dwarf planet in 2006 by the International Astronomical Union (IAU). Note: If we consider only the eight classical planets, Mercury is the smallest. B is correctly matched with 3: Jupiter is the largest planet in the solar system, with a diameter of about 139,820 km. It is a gas giant and has a mass more than twice that of all the other planets combined. It features the iconic Great Red Spot, a giant storm. C is correctly matched with 2: Venus located between Mercury and Earth is the second planet from the Sun. Venus is often called Earth’s "twin" due to its similar size and composition. D is correctly matched with 1: Mercury is the closest planet to the Sun, orbiting at an average distance of 57.91 million km (0.39 AU). It has the shortest orbit of all planets, completing one revolution around the Sun in 88 Earth days.
UPSC 1998Geography · Solar System and Evolution of Earth
Q12. Consider the following statements regarding asteroids: 1. Asteroids are rocky debris of varying size orbiting the sun 2. Most of the asteroids are small but some have diameter as large and 1000 km 3. The orbit of asteroids lies between the orbits of Jupiter and Saturn Of these statements:
Explanation
Statement 1 is correct: Asteroids orbit the Sun in an elliptical path, similar to planets. They are rocky remnants from the early formation of the Solar System about 4.6 billion years ago. Their composition includes metals, silicates, and carbon-rich materials.
Statement 2 is correct: Most asteroids are much smaller, typically less than 1 km in diameter. There are millions of asteroids in the Solar System, ranging in size from tiny pebbles to massive bodies.
Statement 3 is incorrect: Most asteroids are located between the orbits of Mars and Jupiter, not Jupiter and Saturn. This region is called the Main Asteroid Belt, which contains the majority of known asteroids. Some asteroids such as Trojan asteroids, share orbits with Jupiter but are not found in the region between Jupiter and Saturn.
UPSC 1997Geography · Solar System and Evolution of Earth
Q13. The group of small pieces of rock revolving round the Sun between the orbits of Mars and Jupiter are called:
Explanation
Option (d) is correct:
Asteroids are rocky objects that orbit the Sun, primarily found in the Asteroid Belt between Mars and Jupiter. They are remnants from the early formation of the Solar System. They vary in size from small pebbles to Ceres, which is nearly 946 km in diameter and classified as a dwarf planet. Options (a), (b) and (c) are incorrect:
Meteors do not revolve around the Sun in a fixed orbit like asteroids. They are small space debris or fragments of asteroids or comets that enter Earth’s atmosphere and burn up due to friction with the air, producing a bright streak of light (commonly called a shooting star). Comets are not confined to the region between Mars and Jupiter. Comets are icy celestial bodies that originate from the Kuiper Belt or Oort Cloud (far beyond Neptune). They follow highly elliptical orbits around the Sun and develop a glowing coma and a tail when they approach the Sun due to ice subli-mation. Meteorites are meteors that survive their passage through Earth’s atmosphere and land on Earth’s surface. Unlike asteroids they do not orbit the Sun.
UPSC 1997Geography · Solar System and Evolution of Earth
Q14. Which one of the following stars is nearest to the Earth?
Explanation
The Sun, positioned at the center of the Solar System, is the closest star to Earth, with a distance of roughly 93 million miles (approximately 8 light-minutes). Its proximity makes it crucial for life on Earth.
Option (d) is incorrect: Sirius, also known as the Dog Star, is one of the brightest stars visible from Earth. However, it is located approximately 8.6 light-years away, making it significantly farther than the Sun.
UPSC 1997Geography · Solar System and Evolution of Earth
Q15. Which one of the following conditions is most relevant for the presence of life on Mars?
Explanation
The presence of ice caps and frozen water is the most critical condition for the potential existence of life on Mars. Water is fundamental for life as we know it. The presence of frozen water (ice caps) on Mars suggests the possibility of liquid water under certain conditions, making it the most crucial factor for life. Recent discoveries of underground water reservoirs beneath the Martian surface further highlight its importance.
Additional insight:
Mars, the fourth planet from the Sun, is often called the "Red Planet" due to its iron-rich, reddish surface. It has a thin atmosphere primarily composed of carbon dioxide, with traces of nitrogen and argon. Mars has polar ice caps, large volcanoes like Olympus Mons, and a canyon system known as Valles Marineris. The planet experiences seasons, dust storms, and temperature fluctuations. Scientific interest in Mars stems from evidence of ancient rivers, lakes, and possible subsurface water, making it a key target in the search for past or present life.
UPSC 1996Geography · Solar System and Evolution of Earth
Q16. "Diamond ring" is a phenomenon observed:
Explanation
The "Diamond Ring" phenomenon is a striking optical effect observed during a total solar eclipse. It occurs when a small sliver of the Sun’s light is visible around the edge of the Moon, creating the appearance of a brilliant diamond resting on a luminous ring. This effect is typically seen moments just before the eclipse reaches totality or immediately after it ends.
Answer key for these questions
Q
UPSC year
Correct answer
11
1998
(d) A-4; B-3; C-2; D-1
12
1998
(c) 1 and 2 are correct
13
1997
(d) Asteroids
14
1997
(c) Sun
15
1997
(c) Occurrence of ice caps and frozen water
16
1996
(c) only along the peripheral regions of the totality trail
What UPSC has tested in Solar System and Evolution of Earth
The group of small rocky pieces revolving round the Sun between the orbits of Mars and Jupiter are asteroids.
The Sun is the star nearest to the Earth; the average Sun-Earth distance is about 150 million km.
The same face of the Moon is always presented to the Earth because the Moon rotates on its axis in the same time it takes to orbit the Earth.
The Earth is the densest planet in the solar system.
Fresh water available for use is less than 1% of the total water on the planet.
Frequently asked questions
How many previous year UPSC questions are there on Solar System and Evolution of Earth?
This page covers 16 previous year UPSC Prelims GS Paper-I questions on Solar System and Evolution of Earth (Geography), asked from 1996 to 2025. Each has the correct answer and an explanation.
Why do we always see the same face of the Moon?
The Moon takes as long to rotate once on its axis as it takes to go once around the Earth, about 27.3 days. This synchronous rotation keeps one hemisphere facing the Earth at all times.
What lies between the orbits of Mars and Jupiter?
The asteroid belt, a region of rocky debris of varying size orbiting the Sun. Most asteroids lie in this belt, and the largest object in it, Ceres, is classed as a dwarf planet.
How much fresh water is available for use on Earth?
Less than one percent of the planet’s water. Most water is in oceans, and much of the fresh water is frozen in glaciers and ice caps or lies deep underground, which is why usable fresh water is scarce.
