July 12, 2019
Originally published March 30, 2010
image from LROC Featured Image, [NASA/GSFC/Arizona State University]
Looking out of place among all the round, rimmed craters, the elliptical depression on the left is the vent for a circular dark pyroclastic deposit on the south side of the Orientale Basin. We've seen this before in brilliant color as an ultra-closeup, and now this LRO image provides surrounding details. The lack of deposits of volcanic debris around the vent is consistent with there only being an isolated ring of ejecta about 75 km away in all directions. This is a unique volcanic feature on the Moon and there is no obvious reason why it should be located here. Strange. Notice the reduced contrast around the vent? I enhanced the shadowed area of it revealing a hint of a bright region just below its top, this may be layering in the basin deposits that the vent cut through.
LROC WAC image M102788066ME;
Rükl plate VII