alpine valley

There is some debate about how this straight, flat-bottomed trench through the lunar Alps was formed. Some authorities maintain it is a flooded rift in the Moon's surface, whilst others have suggested that is the result of an extremely oblique impact which grazed a channel through the mountains.

Photo: Thierry Legault. The full size original of this and other high definition lunar images may be seen at his High Resolution CCD Imaging site.

Inconstant Moon