Friday, November 30, 2012

Permanently Shadowed Polar Craters

Shown in red are areas of Mercury’s north polar region that are in shadow in all images acquired by MESSENGER to date. Image coverage, and mapping of shadows, is incomplete near the pole. The polar deposits imaged by Earth-based radar are in yellow (from Image 2.1), and the background image is the mosaic of MESSENGER images from Image 2.2. This comparison indicates that all of the polar deposits imaged by Earth-based radar are located in areas of persistent shadow as documented by MESSENGER images. Updated from N. L. Chabot et al., Journal of Geophysical Research, 117, doi: 10.1029/2012JE004172 (2012). 

Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington/National Astronomy and Ionosphere Center, Arecibo Observatory

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