Mars has two natural satellites, named Phobos and Deimos
. Both are small, irregularly shaped moons thought to be either captured asteroids or debris from the early solar system formation
. Phobos is the larger moon, about 22 kilometers in diameter, and orbits very close to Mars, completing an orbit roughly every 7.66 hours
. Deimos is smaller, about 12 kilometers across, and orbits farther away with a period of about 30 hours
. In summary, Mars has exactly two natural moons: Phobos and Deimos
