Astronomy Practice Exam

Which of the following objects travels around the sun in a highly elliptical orbit?

1. A comet

2. An asteroid

3. A meteoroid

4. A planet

The correct answer is: A comet

A comet is the correct choice because it is well-known for its highly elliptical orbits around the Sun. These orbits can take comets far out into the outer regions of the solar system and then swing them close to the Sun. This distinctive orbit results in the dramatic appearance of a comet when it approaches the Sun, as the heat causes its icy components to sublimate and form a glowing coma and sometimes a tail. In contrast, asteroids typically have more circular orbits, especially those found in the asteroid belt between Mars and Jupiter. Meteoroids are smaller fragments and can originate from a variety of sources, but they do not generally follow the same orbital patterns as comets. Planets, like Earth and Mars, move in relatively circular orbits, which are not as elongated or eccentric as those of comets. This distinction in orbital characteristics highlights why comets are classified specifically for their highly elliptical paths.