Surface of Mercury. As the MESSENGER team continues to study the high-resolution images taken during the Mercury fly-by encounter on January 14, 2008, scarps, (cliffs), that extend for long distances are discovered. This frame, taken by the Narrow Angle Camera, (NAC), of the Mercury Dual Imaging System, (MDIS), shows a region of Mercury's surface previously unseen by spacecraft and a large scarp crossing vertically through the scene, on the far right of the image. The width of this image is about 200 kilometers, (about 125 miles), showing that these scarps can be hundreds of kilometers long on Mercury.