This NAC image shows two named craters on Mercury: Raphael, named for the Italian Renaissance painter and Repin, named for the Russian painter of the late 1800s and early 1900s. Raphael is being illuminated by morning sunlight on Mercury, resulting in longer shadows on the left side of the image than on the right side. Repin is the smaller of the two craters (at a diameter of 107 kilometers, or 66 miles) and has a central peak structure. Raphael is a much larger impact feature, and with a diameter of 343 kilometers (213 miles) it would normally be classified as an impact basin. Interestingly, although Raphael is considerably larger than Repin, Raphael does not show any peak structure, such as the peak rings observed in other impact basins of similar or somewhat smaller diameter, of which Raditladi is one example shown in a previously released image (see PIA10378 ). The floor of Raphael is also noticeably smooth, suggesting the presence of volcanic plains that have partially filled this basin. If the accumulated lava flows were sufficiently thick, they might have buried any original topography within the basin. Indeed, some subtle wrinkle ridges around the basin floor may hint at the location of a large interior ring of peaks that has been covered over.
October 6, 2008
Image Mission Elapsed Time (MET): 131774844
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Resolution: 650 meters/pixel (0.4 miles/pixel) in the upper right portion of the image
Scale: The diameter of Raphael is 343 kilometers (213 miles)
Spacecraft Altitude: 25,400 kilometers (15,800 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 .
|Instrument||Mercury Dual Imaging System (MDIS)|
|Extra Keywords||Crater, Grayscale, Shadow, Volcano|
|Date in Caption||2008-10-06|
|Image Credit||NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington|