Phobos
CategoryMoon of Mars
SystemSolar System
Diameter22 km
Orbital Period0.32 days
About Phobos
The larger of Mars two moons. Orbital period of 7 hours 39 minutes is faster than Mars rotation. Getting closer to Mars by 1.8 cm per year and will either crash or break into a ring in 50 million years. Heavily cratered with the Stickney crater dominating one side. Probably a captured asteroid.