Visible near the top of this NAC image are two distinctive craters, imaged for the first time during MESSENGER’s second Mercury flyby. The crater at upper left has light-colored material around its rim and on its floor. In contrast, the larger crater to the right is surrounded by a halo of dark material. Craters with distinctive light and dark materials were also seen during the mission’s first Mercury flyby, such as the craters Poe and Sander located within the Caloris basin (see PIA10603). (The crater Sander was named in April 2008 [PIA10611], while the name of Poe just recently received official approval [PIA11762].) The dark and light materials likely represent rocks with different chemical and mineralogical compositions and as such offer an opportunity to learn about variations in the components that make up Mercury’s surface.

Date Acquired: October 6, 2008
Image Mission Elapsed Time (MET): 131771993
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Resolution: 260 meters/pixel (0.16 miles/pixel)
Scale: This image is about 260 kilometers wide (160 miles)
Spacecraft Altitude: 10,200 kilometers (6,300 miles)

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.