Phobos (moon)
Larger of the two moons of Mars
Phobos is the innermost and larger of the two natural satellites of Mars, the other being Deimos. The two moons were discovered in 1877 by American astronomer Asaph Hall. Phobos is named after the Greek god of fear and panic, who is the twin brother of Deimos and son of Ares (Mars).
From Wikipedia, under CC BY-SA. More on occurri.