image by Tony Gondola
Every place on the Moon is someplace, but many areas don’t have a single structural focus. This corner of southwestern Oceanus Procellarum is part of that latter group. The right half shows where the edge of Procellarum snuck around behind Hansteen (with the bright floor) and Billy (lava-filled), and lapped up on the shores of older battered terrain. This highland terrain is far enough from Orientale (of to the left) that the basin’s massive ejecta flow deposits don’t bury or smear over everything, but basin debris probably coats most things here. Some craters are clearly younger; Sirsalis is one of the largest young craters in this area of the Moon, and the two small one south of it - Sirsalis J and F - are also bright and young. The long linear Sirsalis Rille is younger than the Orientale Basin ejecta, but it is older than the craters J and F that are on top of it. And notice how the rille stops abruptly where it meets Procellarum, whose lavas must be younger than the rille. So there is a history of complex interactions between many different events - and we can distinguish them!
October 23, 2007. 10″ F/7.2 Newtonian, 3x barlow, no filter DMK 21AF04, 200 frame stacks from 2000 frame avi files.
Rükl plates 39 & 40
Tony’s processing of his image
Yesterday's LPOD: Little Rilles and Ponds
Tomorrow's LPOD: 1930′s Moon