... These stars are situated in a star forming region known as N 51. Dione's Lagrange Moon Helene . ... Saturn's Moon Dione . ... The dark spots in the above picture are not photographic defects but an unusual type of interstellar cloud known as a Bok globule. ... Deimos: Small Martian Moon . ... Mars has two tiny moons, Phobos and Deimos. Pictured above is Deimos, the smallest moon of Mars. In fact, Deimos is the smallest known moon in the Solar System measuring only 9 miles across. ...