English: Date acquired: June 23, 2013

Image Mission Elapsed Time (MET): 14301064, 14329855 Image ID: 4310618, 4312682 Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS) WAC filter: 2 (700 nanometers) Center Latitude of Middle Image: 78.81° Center Longitude of Middle Image: 33.63° E Scale: Berlioz crater (outlined in pink) has a diameter of 31 km (19 miles) Projection: Polar stereographic about the north pole, with north to the top Yellow Outline: Radar-bright regions, acquired by the Arecibo Observatory (Harmon et al, 2011, Icarus, 211, 37-50) Red Outline: Region of persistent shadow

Of Interest: Berlioz crater, in contrast to Kandinsky or Prokofiev located at higher latitudes, gets too hot even in the permanent shadow on its floor to have water ice on the surface. However, temperatures slightly below the surface are sufficiently cold for water ice to be stable. The image here provides a look at a crater that is suspected to host buried water ice.

The top image shows a view of Berlioz crater, with the regions that host radar-bright material (yellow) and persistent shadows (red) identified. The middle image was acquired a few hours after the top image, using a longer exposure of the WAC broadband filter, and stretched to reveal the details within the shadowed crater. A distinctively darker region is seen on the crater's floor, which corresponds well with the radar-bright and shadowed regions (bottom image). The darker, low-reflectance material is postulated to be composed of frozen, organic-rich, volatile materials that form through a lag deposit process.

This image was acquired as part of MDIS's campaign to image within regions of permanent shadow in ice-bearing polar craters. Imaging with the WAC broadband clear filter, which has a bandwidth of 600 nanometers and is used for calibration imaging of stars, has the potential to reveal details of shadowed surfaces that are weakly illuminated by scattered sunlight. A variety of image exposure times and viewing conditions are employed to maximize the opportunity to resolve surface features of areas in permanent shadow.