AFOQT Practice Test

What is one common characteristic of all planets in our solar system?

1. They all have rings

2. They all revolve around the sun

3. They all are made of gas

4. They all have at least one moon

The correct answer is: They all revolve around the sun

One common characteristic of all planets in our solar system is that they all revolve around the sun. This is a fundamental aspect of planetary motion, as planets are defined as celestial bodies that orbit a star, in this case, the sun. The gravitational pull of the sun is what keeps the planets in their orbits, allowing them to maintain a stable distance while moving through space. In contrast, not all planets have rings, and while gas giants have rings, terrestrial planets do not. Additionally, while many planets have moons, not all do; for example, Mercury and Venus do not possess any natural satellites. Furthermore, the composition of the planets varies significantly; some are primarily composed of gas (like Jupiter and Saturn), while others are rocky (like Earth and Mars). Therefore, the defining characteristic that unifies all planets in the solar system is their orbit around the sun.