This image, acquired as MESSENGER approached Mercury for its third flyby, shows a large expanse of smooth plains material. The density of impact craters on the smooth plains is less than on the heavily cratered terrain visible in the upper right and lower right corners of the image. The presence of fewer impact craters means that the plains are young compared with the older, battered terrain. Despite their relative youth, the plains have been modified extensively by tectonic forces in Mercury's crust. This modification produced the curving scarps (cliffs) and "wrinkle ridges" that run mostly from top to bottom in the image. The scarps and wrinkle ridges were formed by faulting of near-surface rocks in response to compressive forces within the crust. Another good view of similar plains, scarps, and ridges came from MESSENGER's first flyby.

Date Acquired: September 29, 2009
Image Mission Elapsed Time (MET): 162744209
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Resolution: 410 meters/pixel (0.25 miles/pixel)
Scale: This image is about 400 kilometers (250 miles) wide
Spacecraft Altitude: 15,400 kilometers (9,600 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.