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Scarred Scarp
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Scarred Scarp

September 11, 2013
Date acquired: July 3, 2013 Image Mission Elapsed Time (MET): 15167012 Image ID: 4372157 Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS) Center Latitude: 7.8° Center Longitude: 151.1° E Resolution: 54 meters/pixel Scale: The crater in the center of the image is about 12 km (7.5 mi.) across Incidence Angle: 75.6° Emission Angle: 12.6° Phase Angle: 88.2° North is up in this image. Of Interest: Lobate scarps are one of the most common types of landform on Mercury, and frequently cross-cut impact craters of all sizes. However, the example in this image, termed Alvin Rupes, is one of only a very small subset of scarps that are accompanied by thin, linear depressions on their upper surfaces. One possibility is that these features are graben—fault-bounded troughs that form when rock is extended—like those seen in Caloris basin, for example. If so, then these graben are among the only such structures known to occur outside of volcanically flooded impact basins and craters. This image was acquired as a high-resolution targeted observation. Targeted observations are images of a small area on Mercury's surface at resolutions much higher than the 200-meter/pixel morphology base map. It is not possible to cover all of Mercury's surface at this high resolution, but typically several areas of high scientific interest are imaged in this mode each week. The MESSENGER spacecraft is the first ever to orbit the planet Mercury, and the spacecraft's seven scientific instruments and radio science investigation are unraveling the history and evolution of the Solar System's innermost planet. During the first two years of orbital operations, MESSENGER acquired over 150,000 images and extensive other data sets. MESSENGER is capable of continuing orbital operations until early 2015. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington