Unknown Dark Material on Mercury
Explanation:
What is that strange material on Mercury?
When
flying by Mercury last October,
the robotic
MESSENGER spacecraft imaged
much of the solar system's
innermost planet
in unprecedented detail.
As common in science, new data bring new mysteries.
Pictured above on the lower right, a large crater -- about 100 kilometers across
--
has unusual dark material of unknown composition near its center.
The material's darkness does not appear to be caused by
shadows, as the Sun was near
zenith
when the image was taken.
One origin hypothesis is that the
dark material was uncovered from
beneath Mercury's surface during the impact that created the surrounding crater.
If so, the composition of the dark mound might be similar to the composition of some
mysterious
dark rings
also recently discovered on Mercury.
Alternatively, the dark material could be related to an unusual composition of the
impacting rock.
MESSENGER will
buzz past Mercury again later this year before entering orbit in 2011.
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.
