Thursday, February 27, 2014

Small Impact Craters



The Sun was barely above the horizon when this image was obtained, and the strong shadows emphasize the ruggedness of the terrain. The surface appears to be almost completely covered by -- or saturated with -- relatively small impact craters (about 2 to 3 km in diameter). Many of these may be secondary craters from a large impact in the vicinity, but it is difficult to tell from which one these small craters originate.

This image was acquired as part of MDIS's high-resolution surface morphology base map. The surface morphology base map covers more than 99% of Mercury's surface with an average resolution of 200 meters/pixel. Images acquired for the surface morphology base map typically are obtained at off-vertical Sun angles (i.e., high incidence angles) and have visible shadows so as to reveal clearly the topographic form of geologic features.

Date acquired: January 05, 2012
Image Mission Elapsed Time (MET): 234240885
Image ID: 1226465
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filter: 7 (748 nanometers)
Center Latitude: 77.7°
Center Longitude: 214.9° E
Resolution: 137 meters/pixel
Scale: The scene is about 88 km (55 mi.) wide
Incidence Angle: 88.4°
Emission Angle: 39.7°
Phase Angle: 128.1°
North is up in this image.

Photo credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

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