This image, acquired by NASA’s MESSENGER spacecraft on December 12, 2011, reveals the blue coloration of the 32-mile (52-km) -wide Degas crater located in Mercury’s Sobkou Planitia region.
Degas’ bright central peaks are highly reflective in this view, and may be surrounded by hollows — patches of sunken, eroded ground first identified by MESSENGER last year.
Such blue-colored material within craters has been increasingly identified as more of Mercury’s surface is revealed in detail by MESSENGER images. It is likely due to an as-yet-unspecified type of dark subsurface rock, revealed by impact events.
The slightly larger, more eroded crater that Degas abuts is named Brontë.
The image was acquired with MESSENGER’s Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS), using filters 9, 7, 6 (996, 748, 433 nanometers) in red, green, and blue, respectively.
Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington.