Surface reflectance (relative to perfect Lambertian scattering) measured by MLA from profiles taken at incidence angles less than 30° for Mercury's north polar region. The orange/red areas are those with more than 50% higher reflectance than the regional average, consistent with surface exposures of water ice. Dark areas contain material of unusually low reflectance, about half the typical reflectance of Mercury. The dark areas are believed to be an insulating material that is stable to somewhat higher temperatures than water ice and protects the underlying ice deposits from thermal loss. The values are nearest-neighbor averages. Areas having no data within 2 km are shaded gray.
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.
For information regarding the use of images, see the MESSENGER image use policy.