October 30, 2008

Rotated Mountains?

image by George Tarsoudis, Greece

Most of the Moon's 18 mountain ranges (montes in IAU's Latin) are related to impact basins, typically being part of a basin rim or ring. The Caucaus Mountains, captured here on a slant, are undoubtedly related to a basin, presumably Imbrium to the west, but the oblique angle of the Caucasus makes makes the relation unclear. The fact that the Caucasus are highest on their western edge, with a bright scarp front like the Apennines, suggest that they are part of Imbrium's rim. But if you draw a circle around Imbrium to mark its rim, the Caucasus deviate from the circle; have they somehow been rotated counterclockwise a few degrees? Actually the southern end of the Caucasus - as far north as the area of Theaetetus - lies near the rim circle, but the Caucasus bend toward the east there and are progressively further east of the circle to the north. I have noticed before that Cassini is a break in the Imbrium-circling mountains and have speculated that the area behind (east of it) has been filled in with lava after the Caucasus rotated eastward. Sounds like a good story.

Chuck Wood

Technical Details
22 July 2008. Newtonian 10 inch st f/6.3 + DMK21AF04 + barlow 3X + Red filter with IR-cut; mosaic 7 images, Image processing Registax 4.0 and PS CS3.

Related Links
Rükl plate 13

Yesterday's LPOD: A Sharper Image

Tomorrow's LPOD: Sub-Polar Marker

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