Tuesday, August 31, 2010

Necho's Terraces

Closeup view of the spectacular western terrace of Necho crater. LROC Narrow Angle Camera observation M134388215R, field of view is 660 meters; LRO orbit 4938, July 21, 2010 [NASA/GSFC/Arizona State University].

Brett Denevi
LROC News System

Necho is a Copernican Age 30-km complex crater in the far side highlands (5°S, 123°E). Necho displays beautiful terraced walls formed as a large section of the wall slumped into the crater interior shortly after the impact event.

Reduced resolution NAC mosaic of images M134388215L and R [NASA/GSFC/Arizona State University].

Terraces are typical for craters of this size, though in Necho's case the terraces formed only on the western side.

LROC Wide Angle Camera (WAC) monochrome image of Necho (30 km in diameter) showing the location of the NAC mosaic above. LROC WAC M119048299M [NASA/GSFC/Arizona State University].

What's causing this asymmetry?

It appears that Necho formed on the rim of an older, highly degraded crater. The western half of Necho formed rather normally but the eastern half was affected by this preexisting topography.

The walls on that side were lower, allowing huge flows of impact melt to spill from the crater as seen in the past Featured Image, July 29, 2010 (highlighted again in tomorrow's image.

Necho's serendipitous formation at this site resulted in an extra-beautiful lunar crater. Discover the beauty of Necho's terraces for yourself in the full LROC NAC mosaic.

Related posts: Necho Crater

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