4
Phobos is a small moon of
Mercury
Mars
Venus
Jupiter
2
Phobos is only 
21 kilometers across
60 miles across
10 kilometers across
90 miles across
1
Phobos is only
10,000 kilometers from mars
5,000 kilometers from mars 
6,000 kilometers from mars 
7,000 kilometers from mars
3
The large crater on phobos is called 
Olympus mons
Maxwell mons
Stickey
Valles marineris
3