Cracked mound

Top of a mound with fractured impact melt located on the floor of Anaxagoras crater. Image width is 600 meters. Sunlight is from the bottom-left, NAC M122273232L [NASA/GSFC/Arizona State University].

The irregularly fractured surface in today's Featured Image is on top of a north-western oriented slightly elongated mound on the floor of crater Anaxagoras (image center is 73.748°N, 349.522°E). Anaxagoras (diameter ~ 50 km) is located about 700 km north of Mare Imbrium. The floor of Anaxagoras has an irregularly-shaped central peak. Other portions of the floor are filled with debris and impact melts.

The cracked surface covers only the top portion of the mound. The northern flank of this mound (see figure below) is almost completely covered by boulders, and southern flank is smooth with only a few boulders (as seen in the left hand image below). Why did the cracking happen only at the top of the mound?

One possibility is that the cracked portion is a splashed remnant of impact melt. A solid crust formed where the melt was thickest, and then later, as melt drained downslope, the cracks formed as the crust collapsed.

LRO NAC M122273232L context view around today's Featured Image (blue box area).  A conventional stretch is on the left; on the right, the same image has been stretched to enhance details in the shadowed area. Each image width is about 2 km [NASA/GSFC/Arizona State University].
LROC WAC monochrome mosaic around Anaxagoras crater. Image center is 73.339°N, 349.804°E. The footprint of NAC frame and the location of today's Featured Image are indicated by blue box and yellow arrow [NASA/GSFC/Arizona State University].

The interior of Anaxagoras crater was a Constellation program Region of Interest. With so many exciting features like this one, Anaxagoras crater is an excellent place for humans to explore!

Explore this irregularly cracked ridge and lots of other spectacular impact melt morphologies NAC frame yourself!

Related posts:

Craggy Peak, Impact Melts, Splash and flow, Chaotic crater floor in Tycho, Polygonal fractures on Tycho ejecta deposits, Impact melt in Anaxagoras crater, Exposed Fractured Bedrock in the Central Peak of the Anaxagoras Crater

Published by Hiroyuki Sato on 16 February 2012