Mars
The fourth planet in the solar system. It is one of the terrestrial planets, those made from hard rock, that orbit closest to the Sun. It is named Mars after the Roman god of war. The planet is reddish in colour because of the iron oxide (rust) in its soil. It has a thin atmosphere of mostly carbon di-oxide. There are volcanoes including Olympus Mons, the largest volcano in the solar system, and numerous valleys. Mars has two irregular shaped moons called Deimos and Phobos that are thought to be captured asteroids.