June 3, 2016

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Crater Chains and Unknown Rille

Originally published April 22, 2006

Wolf rille-Wes
Image by Wes Higgins

I like doing the unexpected, and it is certainly unexpected for LPOD to feature images by the same person two days in a row. But here is another image by Wes Higgins. Wes’ image yesterday showed the area southwest of Bullialdus, and this one is to the east of that crater. Like yesterday’s image this one includes secondary crater chains radiating from Bullialdus, off the left side of the frame. These radial chains are visble at the bottom center and left middle parts of today’s LPOD. A much more dramatic chain cuts right across the center of the image, slicing through the southern part of the crater Gould. This secondary crater chain (Rima Gould I on older maps) is not radial to Bullialdus; if it is radial to anything it is to Bullialdus A or, more distantly, König. But I doubt if the chain came from either of those craters - it presumably is from Bullialdus and there must be some bizarre but physically plausible reason to account for it - but I don’t know what that reason is. The real discovery on this image is something you may not yet have noticed. Look carefully. On Mare Nubium between Wolf (bottom) and Gould (middle) is a delicate, tightly sinuous rille. It is clearly visible near the small crater Gould X and extends about 25 km to the south where it ends near the mare ridge north of Wolf. A possible continuation of the rille has an upside down W-shape and runs about east-west. This sinuous rille appears to have been unknown prior to this image. The rille is not in Rükl, the Lunar Orbiter Photographic Atlas, nor Clementine. A short, mid-part of the rille is visible on Consolidated Lunar Atlas sheets F14 and F15. The feature is not convincingly seen as a rille however, anyplace that I am aware of, except on today’s LPOD. I declare that Wes has discovered a previously unknown rille. Congratulations!

Chuck Wood

Technical Details:
Nov 11, 2004. 18″ Reflector, DMK-21F04 camera, 30fps, MAP processing, stack of 500 frames. Wes provides further info about the value of careful processing: The sinuous rille did not even show up until I did a separate alignment on Gould X and then it popped into view.

Related Links:
Rükl plates 53 & 54
Wes’ website

Yesterday's LPOD: Hip, Hip, Hooray for Hippalus

Tomorrow's LPOD: Clumps & Tadpoles


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