May 20, 2013
Image Mission Elapsed Time (MET):
Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
2 (700 nanometers)
A scale bar of 10 km (6.2 miles) is in the image
This image looks like a mistake! However, it was actually acquired just as planned. In order to see the ice-bearing surface
in one of Mercury's permanently shadowed craters, which was being illuminated only by a very small amount of light scattered in from the nearby crater walls, the portion of the image that covers the directly sunlit surface was extremely overexposed. The box in red shows a portion of the image with a different stretch
applied. The crater highlighted here reveals a location of ice buried
beneath a dark, potentially organic-rich, layer of material.
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.
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. In the mission's more than three years of orbital operations, MESSENGER has acquired over 250,000 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
For information regarding the use of MESSENGER images, see the image use policy.