August 3, 2009
Slip Sliding Away
image by Nick Smith, Oxford, UK
Note Look at image carefully before reading caption.
While reviewing the Alpine Valley images in the LPOD Photo Gallery (what a resource! There are now 3,897 images) I was struck by the abrupt offset in the direction of the front of the Alps Mountains just at the Valley. Such imperfections bother me so I did something about it! I used Photoshop to cut Nick's image along the edge of the Valley and slid the northern side 20 km up the Valley to the northeast so that the massive mountain north of the Valley lines up with the front of the Alpes to the south. You can see the unaltered image below. Ideally, there would be a better alignment of details along the Valley to confirm that this movement was correct. But there are only two possible improvements - other than the front lining up better. First, at the upper end of the Valley a faint valley perpendicular to the Valley seems to align with its continuation on the north side. More interestingly, the two mountains that close off the southern end of the Valley from Mare Imbrium are now moved apart and there is a connection to Imbrium at the extreme south. This is pleasing for I would expects an Imbrium radial trough to be open to the mare. But there is still a problem - the northern of the two mountains (on either side of the biggest shadow in the image below) seems to obstruct the passageway. But maybe that was not true before the movement took place. Looking at the Kaguya video that flies along the Valley suggests that those two mountains - which I call the Guardians - have had material slump down their sides, converging into a high spot that may not have existed originally. So perhaps the Guardians originally were not wedged together and lavas flowed from Imbrium through a channel to flood the Alpine Valley, making the sinuous rille that snakes down its middle.
02/15/08; 19.29 UT. C11, Lumenera Infinity 2-1M.
Nick's entire image.
Rükl plates 4 & 12
Nick's astro images
Yesterday's LPOD: Sculptural Sketch
Tomorrow's LPOD: More Rilles