Comments on "October 11, 2015"
There appears to be a true impact concentric crater just north north east of Riccoli, to the top left of today's LPOD of yesteryear. The larger crater appears eroded by time while the inner crater rim looks much sharper, and younger. Here's an LPOD image of the concentric crater with respect to Riccoli:
Ron - yes, an impact inside an impact, but not at all like the smaller concentric craters we normally talk about. Chuck