Asteroids is part of World and Physical Geography. Below are notes on 2 sub-topics, followed by practice MCQs from State PSC and UPSC papers.

Definition and General Characteristics of Asteroids

  • Asteroids are small pieces of rock or rocky debris.
  • They revolve around the Sun.
  • Their main orbit lies between the orbits of Mars and Jupiter (Asteroid Belt).
  • Asteroids vary in size; most are small, but some can have diameters as large as 1000 km.
  • Gibbous phase: Refers to when more than half of the Moon's face is illuminated (includes Waxing Gibbous and Waning Gibbous).
  • Quarter Moon (First/Last Quarter): Refers to when exactly half of the Moon's face is illuminated from Earth, forming a 90° angle between Sun, Earth, and Moon.

The Main Asteroid Belt: Location and features

  • Main Asteroid Belt is located between the orbits of Mars and Jupiter.
  • It hosts the majority of asteroids in our solar system.

Practice MCQs: Asteroids

Definition and General Characteristics of Asteroids

  1. The group of small pieces of rock revolving round the Sun between the orbits of Mars and Jupiter are called:

    Asked in: UPPSC Upper Mains 2006 · UPPCS Prelims 1997

    1. Meteors
    2. Comets
    3. Meteorites
    4. Asteroids
    Show answer

    Answer: D. Asteroids

  2. The 'blue moon' phenomenon occurs when

    Asked in: UPPSC Upper Mains 2007

    1. Two full moons occur in the same month.
    2. Four full moons appear in two consecutive months of the same calendar year.
    3. Two full moons appear in the same month thrice in a calendar
    4. None of the above
    Show answer

    Answer: A. Two full moons occur in the same month.

    The most popular definition of a 'blue moon' is the second full moon in a calendar month.

The Main Asteroid Belt: Location and features

  1. Asteroid belt is situated between the orbit of

    Asked in: WBCS Main Paper 4 2019

    1. Mercury and Venus
    2. Mars and Jupiter
    3. Jupiter and Saturn
    4. Uranus and Neptune
    Show answer

    Answer: B. Mars and Jupiter

    - The asteroid belt is a torus-shaped region containing a large number of irregular shaped bodies called asteroids or minor planets. - It is thought to be composed of remnants of the early Solar System that failed to coalesce into a planet due to Jupiter's strong gravitational influence.

  2. In Solar system, most ‘Asteroids’ lie between the orbits of the following planets :

    Asked in: Lower Subordinate Services Examination 2024 · UPPCS Prelims 2008

    1. Mars and Jupiter
    2. Jupiter and Saturn
    3. Earth and Mars
    4. Venus and Earth
    Show answer

    Answer: A. Mars and Jupiter

    The solar system has distinct regions, including the inner rocky planets, the asteroid belt, and the outer gas giants. The asteroid belt is a significant feature between the terrestrial and Jovian planets. C. (A) is true but (R) is false D. (A) is false but (R) is true Ans: A Assertion (A) is true because the solar wind and radiation pressure from the Sun push the gas and dust particles away from the comet nucleus, forming the tail(s). Reason (R) is true as the tail is indeed composed of gas (sublimated ice) and dust released from the nucleus. (R) correctly explains (A) as the forces from the Sun acting on these released materials are responsible for the tail pointing away from the Sun.