Mars, the Red Planet, is just over half the size of Earth. Its surface features include a vast canyon system, towering volcanoes, and many impact craters. Like Earth, Mars experiences seasons, though the martian year is about twice as long as ours. There are icy caps at the poles, made of a thin layer of frozen water and solid carbon dioxide.
Mars has two tiny moons, Phobos and Deimos. They are both around 12 miles (20 kilometers) across and are probably captured asteroids.
