Phobos Over Mars
Explanation:
Hurtling through space a mere 3,000 miles above
the Martian surface, the
diminutive moon Phobos
(below and left of center)
was imaged against the backdrop of a large
shield volcano by the
Viking 2 Orbiter in 1977.
This dramatic picture
looks down from the Orbiter's viewpoint about 8,000 miles
above the volcano, Ascraeus Mons. Phobos itself is 5,000 miles below
the Orbiter.
North is toward the top with the Sun illuminating the scene from
the South (black dots are reference marks).
For scale,
Ascraeus Mons is about 200 miles across at its base while
asteroid sized Phobos is about 15 miles in diameter.
In this spectacular
moon-planet image,
volcanic calderas (craters)
are visible at the summit of
Ascraeus Mons -- while impact craters on the sunlit side
of Phobos' surface can also be seen!
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.
