pythagoras

This large crater is possibly the deepest walled plan in the Moon's north-west quadrant. It is prominent despite an unfavourable position close to the limb, and would be truly spectacular if it were closer to the centre of the lunar disc.

It is seen here at around day thirteen of the lunation, just after the morning terminator has passed it.

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

Inconstant Moon