Mars has two small moons, Phobos and Deimos, that orbit above the Red Planet's surface. Phobos has been in the news lately because the moon is doomed, and scientists have some new findings about its possible fate. What else do we know about Phobos? Read on to find out.
RELATED: Mars' Moon Phobos Is Double-Doomed
Phobos sports an impact crater that is large relative to its size. Called Stickney, it's about 9.5 kilometers (5.9 miles) across and likely came from an impactor that was so big, Phobos almost broke apart. Secondary craters created by the impact mess up a commonly used technique called "crater counting" to estimate how old the surface of a moon or planet is, according to the
European Space Agency
. An area with fewer craters could be more eroded -- and older -- than an area with more craters. But this does not work on Phobos.