December 11, 2009
Massive crashed disk on Mercury Picture taken by the robotic
MESSENGER spacecraft 2009 July 06.
NASA's own words...
What is that strange material on Mercury?
Picture lower right, a large crater - about 100 kilometers
across - has unusual dark material of unknown composition near
The material's darkness does not appear to be caused by shadows,
as the Sun was near zenith when the image was taken.