Mars is the fourth planet in order of distance from the Sun and the second smallest in the Solar System, after Mercury. It received its name in homage to the god of war from Roman mythology (Ares in Greek mythology), and is also known as the «red planet» due to the reddish appearance that the predominant iron oxide gives it on its surface. Mars is the inner planet farthest from the Sun. It is a telluric planet with a thin atmosphere of carbon dioxide, and it has two small and irregularly shaped satellites, Phobos and Deimos (sons of the Greek god), which appear to be captured asteroids. Its superficial characteristics are reminiscent of both the craters of the Moon and the valleys, deserts and polar ice caps of Earth.
