Thursday, February 18, 2010

Piece by piece, LRO builds the lunar puzzle

LRO's Mini-RF has detailed a important swath of Oceans Procellarum, Above and Below struck upon the Google Earth (v.5+) lunar globe. The "spectacular image strip crossed one of the most volcanically active regions of the Moon, in central Oceanus Procellarum. At top is the Cobra's Head (24.7° N, 310.7° E; ~ 7 km diameter), source vent of the long and sinuous Vallis Schroter, the giant lava channel on Aristarchus Plateau. The full strip continues southward through lava-filled Herodotus, then down the bright and familiar southern wall of the high plateau, into the wider Procellarum basin. Numerous secondaries from the fresher Aristarchus impact next to Herodotus are evident and the strip crosses at least three of the sinuous lava channels to its abrupt end within the Marius Hills complex, including Rima Marius itself (below). The full strip runs from about 7° to 25.5° North latitude roughly along the 311° (
49° West) Meridian. The twelve kilometers wide strip is seen above and below has here been superimposed in three dimensions on the default NASA global photography and topography available everywhere on "Google Moon," except within the Near Side Apollo orbital corridor.

The full version of the Hadley Rille LRO Mini-RF image composed seen inside the images below is available
HERE (614 KB). That Mini-RF image has been added to the multiple-spacecraft (and ground truth) study below of the sinuous Rima Hadley, site of the Apollo 15 mission in 1971. The rille is typically over 1000 meters across and about 300 meters deep. The bright walls of the rille in the Mini-RF image is caused by spacecraft-facing slopes and the greater reflectivity of rougher ground. Bright spots on the smooth mare material in the Mini-RF are caused by fields of surface rocks acting as small corner reflectors for Mini-RF radar waves. Facing northeast in the montage below only the northern half of the full Mini-RF release can be seen. The full release covers an area 12 by 54 kilometers [NASA/GSFC/JHAPL].

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