Deimos
Deimos is smaller than Phobos. Deimos is the farthest one from Mars' moon. Deimos is the smaller of the two moons. It has a length of 9.9 miles. It was named after Terror, a Roman god. Deimos represents dread - a son of Ares and Aphrodite. It was discovered August 12, 1877, by Asaph Hall, an American astronomer. Asaph discovered Deimos while at the U.S. Naval Observatory. He also discovered Phobos while looking for Martian moons.
Asaph Hall named Mars' moons Deimos and Phobos from the mythological sons of Ares and Deimos whose name means flight. Phobos is the brother of Deimos. Deimos circles Mars every 30 hours. Deimos is described as a large rock with several craters. The craters are 2 miles in diameter. Deimos is believed to be made up of ice and carbon-rich rock. Deimos has no magnetic field and no atmosphere.
Phobos
Phobos is much larger than Deimos, about 7.4 times larger. The name Phobos was a Greek god which means fear. Deimos and Phobos were both discovered in 1877. Phobos has a large impact crater, Stickney crater, and is the least reflective body in the Solar System. It is also irregular shaped. Phobos is so close to the planet Mars, it rotates much faster than Mars does. Phobos has a short orbital period and tidal interactions and will eventually collide with Mars or break up into a planetary ring.
Resources
"Solar System Exploration: Planets: Mars: Moons: Deimos: Overview." 2003. 29 Jan. 2013 <http://solarsystem.nasa.gov/planets/profile.cfm?Object=Mar_Deimos>
"Solar System Exploration: Planets: Mars: Moons: Deimos: Overview." 2003. 29 Jan. 2013 <http://solarsystem.nasa.gov/planets/profile.cfm?Object=Mar_Deimos>
e6ee141b8e435ed2.jpg <http://www.redorbit.com/media/uploads/2004/10/4_1707960cc96d39396>