January 17, 2012
Four And One
image by Michael Wirths, Baja California, Mexico
|This is good image of a region with many types of volcanism. The best known volcanoes here are the two Gruithuisen domes (GD), the stubby mounds near upper right. These are made of silica-rich lavas that are much more viscous than normal mare basalts, that is why they are steep-sided. Coming around the low headland is one of the Moon's most bizarre concentric craters (CC) whose inner rim is separated by a series of ball-bearing like mounds from the main rim. Near that is - to use the same phrase - one of the Moon's most bizarre sinuous rilles (to right of "R") - it is braided, and its large vent (to left of "V") makes a curved depression. All the way around the headland is Mairan T, probably the Moon's largest conical volcano. Perhaps high resolution spectral data from LRO will identify the composition of the viscous lavas that formed it. The most normal feature in this province of weirdness is the Mairan Rille (MR), a standard sinuous rille in mare lava.
Yesterday's LPOD: Depicting And Understanding
Tomorrow's LPOD: Outside