January 14, 2008
Image Mission Elapsed Time (MET):
Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
520 meters/pixel (0.32 miles/pixel)
Diameter of Cunningham crater is 37 kilometers (23 miles)
20,300 kilometers (12,600 miles)
Mercury's giant Caloris basin
is the best-preserved large impact basin known on Mercury, and the high density of craters on its floor indicates that the basin is fairly old and probably formed about 3.8 billion years ago. This NAC image shows an area on the plains that partially fill the Caloris basin floor. On the right portion of this image, the light-colored rays emanating from Cunningham crater (named for
the American photographer Imogen Cunningham) show that this crater is relatively young; bright ejecta rays tend to darken with time, as the ejected material is gradually modified by impacting micrometeoroids and solar particles (a suite of different processes that together are called °space weathering°). Relative age relationships such as this one are used to unravel Mercury's geologic history. The similar-sized Kertész crater
is also visible on the left side of this image.
Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
For information regarding the use of MESSENGER images, see the image use policy.