Here we see a rare, historic first. It's an image taken from Europe's
Mars Express orbiter.
The large image is Phobos and Deimos is the smaller image. They
are the two moons of Mars,.... captured, for the first time, in the same graphic picture.
It has been calculated that, in this picture, Phobos was 7,332 miles
from the orbiter and Deimos was 16,280 miles away.
It is believed by many scientists that both of these moons are actually
asteroids that wandered from the Asteroid Belt (between Mars and Jupiter) and were captured by the gravity of Mars.