Wednesday, November 2, 2011

LROC: Fissures and Pit Chains

Fissures and associated pit-chains on the east floor of farside landmark crater Aitken (16.4°S, 173.4°E). LROC Narrow Angle Camera (NAC) M128148929L, LRO Orbit 4018, May 10, 2010 from 55.5 km; incidence angle 44.72° (resolution 58 cm, image field of view width ~336 meters. View the full size LROC Featured Image HERE [NASA/GSFC/Arizona State University].

Hiroyuki Sato
LROC News System

Aitken crater (16.4°S, 173.4°E) is a 135 km diameter crater located very near the center of the farside. Its floor is covered by low-reflectance materials, most likely post-impact lava flows. The eastern edge of the floor is disrupted by an irregular shaped wrinkle ridge that extends in a north-south direction.

Today's Featured Image is about 3.5 km west of the ridges. Here there are parallel linear fissures aligned in NW to SE direction. Pit-chains are located along the fissures, which are likely caused by mass wasting into the subsurface void space.

The largest pit is in the center of the image and shows a relatively rough bottom compared to the surrounding smooth surface. One might expect a small pit like this to be quickly filled by debris from impacts and moonquakes. But this hole seems fresh, which implies a relatively young age.

A virtual oblique view of the western interior of Aitken demonstrating the relative size of the western crater wall, towering over the region of interest. LROC Wide Angle Camera (WAC) 604 nm mosaic, from May 27, 2011, is seen projected on the lunar digital elevation model available to users of the Google Earth application. The rectangle represents the roughly 2900 meter-wide field of view of LROC NAC observation M128148929L [NASA/GSFC/Arizona State University/USGS/Google].

Explore these fissures and pits in the full detail NAC frame yourself!

Related posts:
Extensional Fractures
Tectonics in Mare Frigoris
Stress and pull
Relative age relationships

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