Learn about Mars ' history, features, and exploration by humans and robots. Find out if there is life on Mars and how to get there. Mars is the fourth planet from the Sun, and the seventh largest. It’s the only planet we know of inhabited entirely by robots. Mars Facts Mars is the fourth planet from the Sun and last of the terrestrial planets . Like the rest of the planets in the solar system (except Earth), Mars is named after a mythological figure - the Roman god of war. In addition to its official name, Mars is sometimes called the Red Planet because of the brownish-red color of its surface. Mars is the second smallest planet in the solar system behind Mercury. Learn about Mars , the fourth planet from the Sun, and its features, history, and potential for life. Find out how Mars compares to Earth in size, distance, orbit, rotation, moons, rings, formation, structure, surface, and atmosphere.
