Out on a Limb
Date: 6 Oct 2008
This image shows a portion of Mercury in previously unseen terrain, taken as MESSENGER approached the planet during its second flyby. This view is looking out toward the limb of the planet (north is to the image's right). In the foreground is a region of rough, heavily cratered terrain; a large, ancient two-ring impact basin may be seen at the bottom center of the image. In the distance is a region of younger, tectonically modified smooth plains that have been pockmarked by small craters. The origin of smooth plains on Mercury remains a topic of active inquiry by the MESSENGER team.
Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington