Tuesday, May 15, 2012

LROC: Dark Material Flows

Low reflectance material inside a degraded small crater south of Dopplemayer J near the center of Mare Humorum. Field of view is 290 meters. LROC Narrow Angle Camera (NAC) observation M168476297L, orbit 9962, August 20, 2011; angle of incidence 41.54° at 40 centimeters per pixel resolution from 23.77 kilometers. View the 500 meters wide field of view in the LROC Featured Image released May 15, 2012 HERE [NASA/GSFC/Arizona State University]
Hiroyuki Sato
LROC News System

Today's Featured Image shows off a degraded small crater (400 m in diameter) that appears to have been partly flooded by a low reflectance material. This crater is found 1.5 km south of the southern rim of Doppelmayer J crater (5.68 km in diameter), in Mare Humorum. The boulder-rich portion in the image corresponds to the bottom of an unnamed small crater. Following the slope of this small crater cavity, the low reflectance material appears to have flowed in a southeast direction. The distal edge of this dark deposit is on the top of several boulders, indicating that the small crater preexisted before the emplacement of the dark material. What is this material? Where did it came from?

One likely answer is that an impact melt flow from Doppelmayer J invaded this crater. However, the deposit does not have any cracks nor stream lines which are typical melt flow features. Perhaps a long period of micro-meteorite bombardment degraded the original surface textures disguising the true origin of this deposit.

Area surrounding Doppelmayer J and satellite craters in Mare Humorum, LROC Wide Angle Camera (WAC) monochrome mosaic (100 m/pix), centered near 24.53°S, 318.81°E. The locations of full NAC frame (blue box) and the area highlighted in the Featured Image released May 15, 2012 designated by the yellow arrow [NASA/GSFC/Arizona State University].
Explorer this dark feature and surrounding geology in the full NAC frame yourself, HERE.

Related Posts:
Herigonius K Impact Melt Flow
Impact melt tongue
Rootless impact melt flows
Splash and flow
Impact Melt Lobes

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