atlas and hercules

This pair of craters, both with unusually mythological names, have a contrasting appearance, for while the floor of Atlas (to the east) is covered in rilles, Hercules has been flooded with lava, and is largely smooth and dark. Hercules is fractionally deeper, and when the terminator is close and the sunlight is low this can mean its floor is totally black whilst it neighbour's is largely illuminated.

Photo: António Cidadão. His Home Page of Astrophotography includes stereograms, animations, and "Seven Craters a Week" from his forthcoming photographic lunar atlas.

Inconstant Moon