Closeup view of the spectacular western terrace of Necho crater. NAC image M134388215R; scene width is 660 m [NASA/GSFC/Arizona State University].
Necho is a Copernican-aged, 30-km complex crater located in the far side highlands at 5°S, 123°E. Necho displays beautiful terraced walls, which 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.
WAC monochrome image of Necho crater (30 km in diameter) and the location of the NAC mosaic above. Image 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 crater formed rather normally, but the eastern half was affected by this preexisting topography. The walls on that side of the crater were lower, which allowed huge flows of impact melt to spill from the crater, as seen in this past featured image, and will be 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!