Astronomy Practice Exam

How is an asteroid classified?

1. A small and icy object that orbits the Sun

2. A large and luminous ball of gas

3. A small and rocky object that orbits a star

4. A moderately large object that orbits a planet

The correct answer is: A small and rocky object that orbits a star

An asteroid is classified as a small and rocky object that orbits a star, specifically our Sun. This classification is based on its composition and orbital characteristics. Asteroids are primarily found in the asteroid belt, which is located between the orbits of Mars and Jupiter. They are generally remnants from the early solar system that never coalesced into a planet due to the gravitational influence of nearby Jupiter. In terms of composition, asteroids are mostly made of rock and metal, distinguishing them from other small celestial bodies like comets, which are primarily composed of ice and dust. This differentiation is crucial for understanding their physical properties and the role they play in the solar system. The classification reflects their size as well—while some asteroids can be quite large, they still remain significantly smaller than planets. This definition helps astronomers identify and study these objects, contributing to our understanding of the solar system's formation and evolution. Other classifications, such as comets and meteoroids, have different defining characteristics, which helps to further differentiate these components of our solar system.