Phobos: Doomed Moon of Mars
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 robotic
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.
A recent analysis
of the long grooves indicates that they may result from global stretching caused
by
tides --
the differing force of Mars' gravity on different sides of
Phobos.
These grooves may then be an early phase in the
disintegration of
Phobos into a ring of debris around Mars.
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Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell
(USRA)
NASA Web Site Statements, Warnings,
and Disclaimers
NASA Official: Jay Norris.
Specific
rights apply.
A service of:
LHEA at
NASA /
GSFC
& Michigan Tech. U.
