Favorite Satellite in our Solar System

Take a moment and think about it. When was the last time you thought about your favorite satellite in the Solar System?

Phobos.

Some facts about Phobos:

One of two sattelites that orbit mars, Phobos is an irregular moon. Phobos is one of the least-reflective bodies in the solar system. Spectroscopically it appears to be similar to the D-type asteroids. Because of its shape alone, the gravity on its surface varies by about 210%; the tidal forces raised by Mars more than double this variation (to about 450%) because they compensate for a little more than half of Phobos' gravity at its sub- and anti-Mars poles.

Phobos is heavily cratered. The most prominent surface feature is Stickney Crater. The impact that created Stickney must have almost shattered Phobos, and many grooves and streaks also cover the oddly shaped surface. The grooves are typically less than 30 m deep, 100 to 200 m wide, and up to 20 km in length, and were originally assumed to have been the result of the same impact that created Stickney.

An image (in false color) of Stickney Crater.