Deimos (or Mars II) comes from the Greek word for terror. It is the smaller moon of Mars. Its orbital period is 30.3 hours, which is 1.263 days.
Deimos is only 15 kilometers in diameter. It is covered with craters, as Earth's moon and other bodies without an atmosphere are.
It is named after the god Deimos in Greek mythology, who was one of Mars' sons, and means Panic.
The other moon, Phobos, is the larger of the two.