A new imaging campaign during MESSENGER's extended mission is acquisition of a global albedo map of Mercury's surface. "Albedo" is a term used to describe the fraction of light incident on a surface that is scattered back and can be measured by an observer (such as MDIS). In other words, the albedo is the inherent reflectance of a material.
The best images for discerning variations in albedo on the surface are acquired when the Sun is overhead, so these images typically are taken with low incidence angles, like the image shown here. This image illustrates a wide variety of features with different albedo values, such as the light-colored rays of Dominici , dark material excavated from a crater located to Dominici's southwest, and very bright material due to hollows on the rim of and interior to Dominici. The albedo base map is a major mapping campaign in MESSENGER's extended mission and will cover Mercury's surface at an average resolution of 200 meters/pixel.
March 29, 2012
Image Mission Elapsed Time (MET): 241540715
Image ID: 1580606
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: 0.06°
Center Longitude: 323.7° E
Resolution: 189 meters/pixel
Scale: The rayed crater Dominici has a diameter of 20 kilometers (12 miles)
Incidence Angle: 0.7°
Emission Angle: 58.3°
Phase Angle: 57.7°
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. Visit the Why Mercury? section of this website to learn more about the key science questions that the MESSENGER mission is addressing. During the one-year primary mission, MDIS acquired 88,746 images and extensive other data sets. MESSENGER is now in a year-long extended mission, during which plans call for the acquisition of more than 80,000 additional images to support MESSENGER's science goals.
These images are from MESSENGER, a NASA Discovery mission to conduct the first orbital study of the innermost planet, Mercury. For information regarding the use of images, see the MESSENGER image use policy .
|Instrument||Mercury Dual Imaging System (MDIS)|
|Extra Keywords||Crater, Grayscale, Map, Radio|
|Date in Caption||2012-03-29|
|Image Credit||NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington|