Explanation:
This moon is doomed.
Mars,
the red planet named for the
Roman god of war, has two tiny moons,
Phobos and
Deimos, whose
names are derived from the Greek for Fear and
Panic.
These martian moons may well be captured
asteroids
originating in the main asteroid belt between Mars and
Jupiter
or perhaps from even more distant reaches of the Solar System.
The larger moon, Phobos, is indeed seen
to be a cratered, asteroid-like object in this
stunning color image from the
Mars Reconnaissance Orbiter,
recorded at a resolution of about
seven meters per pixel.
But Phobos
orbits so close to Mars - about 5,800 kilometers above the surface compared to 400,000 kilometers
for our Moon - that gravitational
tidal forces
are dragging it down.
In 100 million years or so Phobos
will likely be shattered by stress caused by the
relentless
tidal forces, the debris forming a decaying ring around Mars.
digg_url = 'http://apod.nasa.gov/apod/ap080414.html'; digg_skin = 'compact';
