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Crater on the Moon

Crater on the Moon

Named for St Catharina or Catherine of Alexandria, this is one of three large craters that run along the northwestward extent of Mare Nectaris in the central southern parts of the Moon's visible face. While the other two craters in this group, Theophilus and Cyrillus, are so close together that one actually overlaps the other, Catharina lies somewhat apart from them to the southwest.

Catharina stands in a rugged and broken landscape. Running north-to-south alongside its western rim is a channel, beyond which lies the beginnings of the southern range of the Rupes Altai. The crater Catharina itself is heavily eroded, with a worn and disintegrating rim surrounding a crater floor some 97 km in diameter.

The crater floor is far from even, and it is broken in places by a network of rilles. It also contains numerous examples of further impacts, evidently postdating the formation of Catharina itself. The result is a scattering of tiny craters within and around Catharina, and also evidence of some much larger impacts. Most notable among these is an interior crater designated Catharina P which, at 46 km in diameter, covers much of Catharina's northern quadrant. Catharina P has itself suffered further impacts, and its eastern wall (which it shares with the main crater) is broken by the 17 km crater Catharina G.