This image, taken with the MDIS Narrow Angle Camera (NAC), shows two named craters imaged by both MESSENGER and Mariner 10. At the bottom of the image are the double rings of Bach, a peak-ring basin named for the German composer J.S. Bach. The bright crater toward the top is Alencar, named for the Brazilian novelist JosÚ de Alencar; the central peak structure and terraced walls make it a good example of a complex crater.
This image was acquired as part of MDIS's high-resolution surface morphology base map. The surface morphology base map will cover more than 90% of Mercury's surface with an average resolution of 250 meters/pixel (0.16 miles/pixel or 820 feet/pixel). Images acquired for the surface morphology base map typically have off-vertical Sun angles (i.e., high incidence angles) and visible shadows so as to reveal clearly the topographic form of geologic features.
On March 17, 2011 (March 18, 2011, UTC), MESSENGER became the first spacecraft ever to orbit the planet Mercury. The mission is currently in its commissioning phase, during which spacecraft and instrument performance are verified through a series of specially designed checkout activities. In the course of the one-year primary mission, the spacecraft's seven scientific instruments and radio science investigation will unravel the history and evolution of the Solar System's innermost planet. Visit the Why Mercury? section of this website to learn more about the science questions that the MESSENGER mission has set out to answer.
Date acquired: May 03, 2011
Image Mission Elapsed Time (MET): 212948404
Image ID: 208567
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: -67.10 ░
Center Longitude: 254.8 ░ E
Resolution: 295 meters/pixel
Scale: The Bach basin is 225 km (140 miles) across.
Incidence Angle: 67.0 ░
Emission Angle: 36.1 ░
Phase Angle: 103.1 ░
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.