Deimos
Mars' smaller, outer moon: from the ground, a bright star that drifts slowly across the sky.
Deimos orbits a little slower than Mars turns, so it rises in the east like our Moon, but takes about two and a half days to cross the sky.
It is only 12 km across: from Mars it looks like a bright star rather than a disc.
Facts
- Size
- 15 × 12 × 11 km
- One orbit
- 30 h 18 min
- Height above Mars
- about 20,000 km