- MEAN RADIUS: 7.5×6.1×5.2 km
- MASS: 2.38 × 1018 g
- GRAVITY: Negligible
- ORBIT PERIOD: 1.2624407 (Earth days)
- ROTATION PERIOD: Synchronous
- ECCENTRICITY OF ORBIT: 0.0005
Named after the Roman god of dread, Deimos, the smaller and outermost of Mars' two moons, whirls around Mars every 30 hours. It is the smallest known moon in the solar system. In Greek mythology, Deimos is one of the sons of Ares (Mars) and Aphrodite (Venus). Deimos is Greek for Panic.
It was discovered August 10, 1877 by Asaph Hall. Viking 1 photographed it during a flyby in 1977.
Deimos also has a thick regolith, perhaps as deep as 100 meters, formed as meteorites pulverized pounded the surface. Deimos is a dark body that appears to be composed of C-type surface materials, similar to that of asteroids found in the outer asteroid belt.
