Mars has 2 moons: Phobos and Deimos. Like Earth’s Moon, Phobos and Deimos always present the same face to their planet. Both are lumpy, heavily-cratered and covered in dust and loose rocks. They are among the darker objects in the solar system. The moons appear to be made of carbon-rich rock mixed with ice and may be captured asteroids.
| 1. Phobos | 2. Deimos |
| Name | Phobos |
|---|---|
| Discovery date | 1877 (A. Hall) |
| Semi-major axis | 9380 km |
| Diameter | 27 x 22 x 20 km |
| Orbital period (Length of a year) |
0.319 Earth days |
| Name | Deimos |
|---|---|
| Discovery date | 1877 (A. Hall) |
| Semi-major axis | 23 460 km |
| Diameter | 15 x 12 x 10 km |
| Orbital period (Length of a year) |
1.262 Earth days |
