September 29, 2013
image by George Tarsoudis, Greece
It used to be that there were professional astronomers and amateurs. But now, with this image and others that LPOD has featured recently, there is only excellent imaging, whether from a giant telescope, a backyard one or an orbiting camera. I am amazed to see a terrestrial image of this scale and quality. The dramatic lighting highlights the ejecta from Theophilus, with the smooth impact melt ponds just north of the crater's rim. Also very conspicuous is a small rille that looks like a twig with branches at the top end. This has been imaged before but it is more distinctive here.
|The rille also crosses a circular rise that George proposes is a
megadome similar to the Valentine Dome. The dome (outlined
in red) is undetectable in the image due to the distractions of
Theophilus' ejecta, but using LRO QuickMap elevations George
found that it is roughly 85 km wide and 300-400 m high. The
existence of the dome may explain the location of the rille. Few
rilles occur in this area, but a rille does cross the Valentine
Dome so this may be a similar feature.
Yesterday's LPOD: Extreme Makeover
Tomorrow's LPOD: A Bridge Too Far, an Observation Quite Good