I had a nice look this evening at the lunar crater J. Herschel. It was just past the terminator with the entire rim and floor illuminated. But what was interesting was that there was a dark shadow all the way around the inside of the rim. It appears to be a depression on the inner side of the rim. Or perhaps the entire floor is raised in a dome shape. There is also a not very prominent central peak. I've never seen a crater quite like that before. But it does make sense physically, I guess; the process that makes central peaks might also raise the entire floor. If it solidified more quickly than usual it might look like this.

Equipment: TV Pronto, 4.8 and 7mm Naglers, 2x TV Barlow. Despite the heat this afternoon by evening was just about perfect for astronomy in the hills above Redwood City. About 80 degrees (F), light breeze just enough to take the bite off the heat but not enough to spoil the seeing. There would be a lot more astronomers if it were always this way :-)