Mars Has Two Small Moons

Phobos and Deimos, two minor moons of Mars, could be impacted by asteroids. They are shaped like potatoes because they don't have enough mass to float spherically due to gravity. The horses that pulled the chariot of Ares, the Greek god of war, gave the moons their names.

The bigger and innermost moon, Phobos, is extensively cratered and has deep ridges on its surface. It is slowly approaching Mars and will either collide with the planet or disintegrate within 50 million years.

Phobos and Deimos are roughly equal in size, although Deimos orbits Mars at a distance of 2.5 times greater. Strangely shaped, Deimos has a surface covered in loose material that frequently covers the craters, giving it a smoother appearance than pockmarked Phobos.