Phobos is an odd moon. It's positively tiny, having a radius of just 11 kilometers. Because of its small size, it's more potato-shaped than spherical—there's not enough gravity to force the whole thing into a sphere.

But Phobos is a tantalizing place for a NASA mission. Its complete lack of atmosphere makes it easier to land on than Mars itself, and, as Buzz Aldrin has pointed out many times, it would make a good base station for any sort of human colony on Mars itself.

A support team could set up shop on Phobos and could then act as a communications middleman between Earth and Mars, which would significantly reduce the amount of time it takes to send a message from a Martian colony to Earth.