April 30, 2011
image by Mario Weigand, Offenbach am Main / Germany
One of the remarkable things about whatever the material is that covered the original floor of Albategnius is that it didn't spread and smooth out underlying irregularities. Mario's marvelous low light view captures the shallow depressions that mark buried craters and crater chains. The surface is relatively smooth so the material did flow, but it seems to have been stiff enough to not be compressible and to not fill in nearby lows. If water had been splashed into the crater its fluidity would allowed it to achieve an equipotential surface, obliterating the low spots. I suppose that a mathematically clever person could derive innformation about the physical characteristics of the flow material - presumably Imbrium ejecta (because there are no dark halo craters indicating buried basalt). But I am satisfied to have a qualitative understanding and to enjoy the impact crater placed on the crater's central peak, ready to lure out old defenders of volcanism.
OT: Lunar green flashes.
See bottom of image
Rükl plates 44
Two earlier views: 1 and 2
Yesterday's LPOD: Sizing Up the Solar System
Tomorrow's LPOD: A Little Slice of Solitude