Shadow at the Lunar South Pole
Credit:
In 1994, the space probe Clementine spent 70 days in lunar orbit mapping
the Moon's surface.
Shown above is a dramatically detailed composite view
centered on the Moon's South Pole constructed from 1500 Clementine images.
The top half shows the part of the Moon which
faces the Earth while the bottom half is the
lunar Farside. The images reveal a major
depression very near the South Pole itself, probably caused by the impact of
a comet or
asteroid.
The shadow region near the impact site is extensive
and may be permanent - creating an area cold enough to trap water of
cometary origin as ice.