Farside Highlands Volcanism
December 7, 2012
Since the domes in the Compton-Belkovich area are rounded and smooth (excepting the boulders scattered across the summit) they are not easy to spot. At sunrise and sunset (above) even smooth topography casts long shadows. In this case the Sun is 13° degrees above the horizon, showing that the slopes of the dome are steeper than 13°, an important clue to unraveling its origin. Steeper slopes often mean more viscous magma, which in turn points toward more silica rich compositions. Same dome, lower Sun. The low Sun brings out small topographic features, note the summit boulder shadows. Image is 600 m on a side, NAC image number M119198897R [NASA/GSFC/Arizona State University].