Up Close With Proclus

Originally published December 7, 2004

Image Credit: NASA AS15-81-10929

Up Close With Proclus

Proclus is one of the brightest - and thus presumably youngest - craters on the Moon. As the Apollo image on the right illustrates, Proclus has a very sharp rim crest and its 1060 m deep floor is filled with slump blocks (S) of material that has slid down its steep walls. This is a common style of modification for craters intermediate in diameter between simple bowls and larger, more complex terraced craters. If 28 km wide Proclus has a central peak it is hidden from view by the wall rubble. The left Apollo view shows a different Proclus than I would expect. The rim crest is not as sharp as it appears in the right image, and the rim doesn't rise as far above the surrounding terrain as I thought it would. If Proclus has formed on the nearby Mare Crisium its rim would probably be strongly differentiated from the mare surface. Proclus seems less fresh and less spectacular because of the rugged terrain it sits on.