QUESTION:
Since Phobos orbits Mars faster than Mars rotates, and Deimos orbits Mars
slower than Mars rotates, does it appear from the surface that Deimos and
Phobos are traveling in different directions? And if they orbit in the same
plane, would the moons have a conjunction? Would this only be visible
(Phobos right in front of and probably eclipsing Deimos) from the equator?

ANSWER from Bob Haberle on August 14, 1997:
Yes, indeed! Phobos and Deimos would appear to be traveling in opposite
directions: Phobos would rise in the west and set in the east, while Deimos
would be more conventional and rise in the east and set in the west.
However, Phobos and Deimos do not orbit in quite the same plane so eclipses
would be rare.