Phobos

Phobos is a moon orbiting Mars in the Sol system.
== History ==
Phobos was formed unusually, it being a celestial body that may not be a singular piece. It may, in fact, be composed of many smaller objects held together by a thin crust which did not have enough gravitational force to coalesce into a ball.
Unlike most satellites, Phobos does not have a stable orbit, as it moves approximately 2 meters closer to its planet every hundred years. It is estimated that it will collide with Mars in 30 to 50 million years, forming a planetary ring system.
Category:Planets in Solar System