Phobos

Phobos, also known as Mars I, is the larger moon of Mars, the other one Deimos. The moon resembles a potato to me. I mean, an object 7 miles across can't use its own gravity to shape it into a sphere. Fun Fact: Phobos orbits closer to its host planet than any other moon in the solar system! Maybe that's why Phobos is gonna crash down onto Mars sooner or later. Also, you can jump off Phobos. Hmm, that sounds FUN! Well, you'll end up around Mars, slowly run out of oxygen and die. That doesn't sound fun anymore, does it?