Seduced by the Dark Side: Nasa Messenger Mission Image - Release Date 14 Oct 2011

Date acquired: September 20, 2011 Image Mission Elapsed Time (MET): 224970864 Image ID: 781860 Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS) WAC filter: 5 (628 nanometers) Center Latitude: -17.18° Center Longitude: 25.99° E Resolution: 2275 meters/pixel Scale: Derain crater is 168 km (104 miles) in diameter. Incidence Angle: 33.5° Emission Angle: 0.4° Phase Angle: 33.7° Of Interest: This image, taken by the Wide Angle Camera (WAC), shows the unique dark outline of Derain crater. Located in the upper left, Derain was first viewed during MESSENGER's second flyby and subsequently named in 2009. The impact appears to have exposed "LRM", or low reflectance material--one of the major global compositional units found on Mercury. Also visible in this image are some of Debussy's rays, as well Berkel crater, the small dark spot surrounded by bright ejecta located just above the center of the image. This image was acquired as part of MDIS's color base map. The color base map is composed of WAC images taken through eight different narrow-band color filters and will cover more than 90% of Mercury's surface with an average resolution of 1 kilometer/pixel (0.6 miles/pixel). The highest-quality color images are obtained for Mercury's surface when both the spacecraft and the Sun are overhead, so these images typically are taken with viewing conditions of low incidence and emission angles.

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