The Terrestrial Planets

Now you know that the terrestrial planets have both similarities and differences. In this topic, you explored why the four inner planets are all considered terrestrial planets. You learned that Mercury is heavily cratered, Venus is very hot, Earth is perfectly placed, and Mars is the red planet. One huge difference is the fact that only two of the four planets - Earth and Mars - have moons. In addition, you examined the Moon's geography, which is full of craters, highlands, maria, and rill.