Astronomy Practice Exam 2025 – Complete Preparation Guide

The accurate characterization of terrestrial planets is that they are close to the Sun and have rocky surfaces. Terrestrial planets in our solar system include Mercury, Venus, Earth, and Mars. These planets are distinguished by their solid, rocky crusts, compared to gas giants, which are predominantly composed of gases and have no solid surface.

The proximity to the Sun plays a significant role in their formation and composition. Being closer to the Sun results in higher temperatures which causes lighter gases to be stripped away, allowing these rocky planets to develop solid surfaces. This is a crucial factor differentiating terrestrial planets from gas giants, which are located further from the Sun and are primarily made up of hydrogen and helium.

The other options do not accurately represent terrestrial planets: they are not gas giants, are not positioned far from the Sun, and do not revolve around a different star. This reinforces the significance of their rocky nature and their relative nearness to the Sun in classifying terrestrial planets.