AFOQT Practice Test

What is the main characteristic of gas giants compared to terrestrial planets?

1. Solid surfaces

2. Lack of rings

3. High density

4. Thick gaseous atmospheres

The correct answer is: Thick gaseous atmospheres

The main characteristic of gas giants, such as Jupiter and Saturn, is their thick gaseous atmospheres. These planets are composed primarily of hydrogen and helium and have very deep atmospheres with extreme pressure and temperature variations. Unlike terrestrial planets, which have solid surfaces and are made up of rock and metal, gas giants lack a well-defined solid surface and are instead enveloped in layers of gas that can be hundreds to thousands of kilometers thick. This fundamental difference in composition and structure is what sets gas giants apart from terrestrial planets, which are smaller, denser, and have solid surfaces. The presence of the thick gaseous atmospheres contributes to various atmospheric phenomena, including storms, cloud bands, and complex weather systems that are not found in terrestrial environments.