The Cutting Edge
This WAC image features a long, curving scarp (cliff) or rupes on Mercury. Based on the law of superposition we know that the crater formed before the scarp; the scarp bisects or "cuts" the edge of the crater. Scarps such as this one formed as the planet's interior cooled and contracted. The stresses caused by the shrinkage caused the crust to fracture, and the section of crust to the east (right) was pushed over the section to the west (left), greatly deforming the 23 km-diameter crater.
Date acquired: May 07, 2011
Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington