The two moons of Mars, Deimos and Phobos, are dark and feature numerous craters. They are covered with dust and rocks and show evidence of landslides.
Deimos and Phobos are two of the smallest moons in the solar system. Phobos features a crater that stretches almost six miles, covering close to half its width. Phobos is slightly larger than Deimos and circulates closer to Mars than any other moon does to its planet. Deimos and Phobos were discovered by Asaph Hall in 1877 and named after the sons of the Greek god Ares, who was the Greek equivalent of the Roman god Mars.