Phobos and Deimos, the two moons of Mars, rotate on their axes:
A)so that they always have the same sides facing each other as they orbit Mars.
B)with no particular relationship to their revolutionary periods, that is, nonsynchronously.
C)to maintain the same face toward the Sun at all times, because of tidal forces.
D)synchronously, keeping one face toward Mars at all times.

Question

Quizplus · Accepted Answer

Phobos and Deimos rotate synchronously, meaning they keep the same face toward Mars at all times. This is a result of tidal forces between the moons and Mars, similar to how the Moon keeps one face toward Earth.

Phobos and Deimos, the Two Moons of Mars, Rotate on Their