March 29, 2011
Image Mission Elapsed Time (MET):
Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
12 (828 nanometers)
The edges of the image are about 100 km (62 mi.) long.
Visible in this image are curving ridges, some of which form circular outlines. One is in the left corner, and several larger ones are arranged vertically down the center-right part of the image. These circular features mark the rims of "ghost craters" - impact craters that were subsequently buried by the voluminous volcanic lavas that form the plains in this part of Mercury. No doubt some craters were buried completely and now are entirely hidden, whereas others reveal their presence by the ridges that formed when the volcanic cover sagged over the crater rims or in response to modest horizontal contraction of the region.
This image was collected during the spacecraft's commissioning phase, shortly after entering orbit around Mercury. The image was binned on the spacecraft from its original 1024 × 1024 pixel size to 256 × 256. Binning helps to reduce the amount of data that must be stored on the spacecraft's solid-state recorder
and downlinked across interplanetary space from MESSENGER to the Deep Space Network on Earth. The image here has been placed into a map projection with north at the top.
The MESSENGER spacecraft is the first ever to orbit the planet Mercury, and the spacecraft's seven scientific instruments and radio science investigation
are unraveling the history and evolution of the Solar System's innermost planet. Visit the Why Mercury?
section of this website to learn more about the key science questions that the MESSENGER mission is addressing. During the one-year primary mission, MDIS is scheduled to acquire more than 75,000 images in support of MESSENGER's science goals.
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.