Shortly following MESSENGER's closest approach to Mercury on January 14,
2008, the spacecraft's Narrow Angle Camera (NAC) on the Mercury Dual
Imaging System (MDIS) instrument acquired this image as part of a mosaic
that covers much of the sunlit portion of the hemisphere not viewed by
Mariner 10. Images such as this one can be read in terms of a sequence of
geological events and provide insight into the relative timing of
processes that have acted on Mercury's surface in the past.
The double-ringed crater pictured in the lower left of this image appears
to be filled with smooth plains material, perhaps volcanic in nature. This
crater was subsequently disrupted by the formation of a prominent scarp
(cliff), the surface expression of a major crustal fault system, that runs
alongside part of its northern rim and may have led to the uplift seen
across a portion of the crater's floor. A smaller crater in the lower
right of the image has also been cut by the scarp, showing that the fault
beneath the scarp was active after both of these craters had formed. The
MESSENGER team is working to combine inferences about the timing of events
gained from this image with similar information from the hundreds of other
images acquired by MESSENGER to extend and refine the geological history
of Mercury previously defined on the basis only of Mariner 10 images.
This MESSENGER image was taken from a distance of about 18,000 kilometers
(11,000 miles) from the surface of Mercury, at 20:03 UTC, about 58 minutes
after the closest approach point of the flyby. The region shown is about
500 kilometers (300 miles) across, and craters as small as 1 kilometer
(0.6 mile) can be seen in this image.
Mission Elapsed Time (MET) of image: 108828359
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.