Saturday, August 17, 2013

Fresh crater in the farside Saenger crater group

Fresh, unnamed crater in the farside Saenger crater group
A very fresh 3.2 km crater, with a bright, wide-ranging ejecta field, unusual melt erosion and ponding on its floor, blasted into a ridge in the Saenger crater group;  where the farside highlands begin, beyond the Moon's eastern limb at 4.579°N, 101.129°E.

Because it's nested on the northeastern side of a broad ridge, trending from southwest to northeast this very youthful crater's southeastern wall, rising 1180 meters above the level floor far below, is twice the height or more than its northwestern opposite.. Landslides of very fine materials run down the higher walls while the northwest is dominated by melt-carved ravines and boulders either draped with, or entirely composed of, dark melt and melt-fused composites.

There is also a hint of darker materials excavated in thin streams in the crater's ejecta immediately encircling its rim. The crater, which eventually deserves a name, is shown above in a 5.5 km-wide field of view from LROC Narrow Angle Camera (NAC) mosaic M167539260LR, spacecraft orbit 9824, August 9, 2011; 46° angle of incidence, resolution 61 centimeters per pixel from 59.58 km [NASA/GSFC/Arizona State University].

Heading east, following the equator, the high elevations distinctive to the Moon's farside, come into their own beyond the vast swirl fields of Mare Marginis. The 3.2 km crater immediately east of center in this field of view is nested in a wide ridge with an origin deeper in the distant past history of lunar morphology than Saenger crater, partly visible on the right. LROC Quick Map GLD100 DEM [NASA/GSFC/Arizona State University].
The global medium-resolution mosaic swept up by the PRC's Chang'e-2 (2011), under full illumination of a high Sun, offers good appreciation for the scope of the unnamed crater's ejecta rays system. This area is missing from Clementine (1994) albedo maps [CLEP/CNSA].
Some Related Posts:
Convergence (August 8, 2013)
Melted Moon (July 31, 2013)
The view inside a tilted crater (July 23, 2013)
Complicated Crater (June 19, 2013)
"Ka Pow!" on Joliot's central peaks (June 18, 2013)

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