March 4, 2012
image by Mario Weigand, Offenbach am Main / Germany
Mario must have had a magical night of imaging on March 1 for he has uploaded to the LPOD Photo Gallery 13 fantastic images including this dramatic view of Eratosthenes. This image highlights the radiating ridges and valleys of the crater's continuous ejecta blanket. But what immediately astonished me was the faint rille along the eastern edge of the image. I don't remember noticing this before and don't see it on any other Photo Gallery images. It is visible on the LRO Quick Map, but the higher Sun makes it less conspicuous. This is a continuation of Rima Bode which was the source for the Moon's largest pyroclastic deposit, but there is no darkening around this piece of rille so perhaps pyroclastics did not erupt from it. The rille is interupted in one spot, suggesting that younger lavas buried it. I wonder why the rille abruptly changed direction when it entered the mare. Or is this very thin rille part of an older circumferential system associated with the putative Aestuum Basin? Each image that better shows a delicate feature tells us more about the Moon, but often raises new questions too. That is why wonderful images like this are so exciting to examine.
Rükl plate 12
Yesterday's LPOD: Invisible Melt
Tomorrow's LPOD: Lunar Mosaic of the Day