Many craters experience partial or substantial collapse of their inner walls after formation. Such collapses are often manifest as individual slumps, but arcuate terraces may also form. In this example, an unnamed crater about 50 km due south of Calypso Rupes displays a terrace that circles almost the entire crater wall. The crater's floor appears relatively smooth in this image, which was taken when the Sun was high in the sky (~30° from vertical); this material is either impact melt or lava, though it is not of sufficient volume to have buried the crater's diminutive central peak.

This image was acquired as a high-resolution targeted observation. Targeted observations are images of a small area on Mercury's surface at resolutions much higher than the 200-meter/pixel morphology base map. It is not possible to cover all of Mercury's surface at this high resolution, but typically several areas of high scientific interest are imaged in this mode each week.

Date acquired: January 13, 2014
Image Mission Elapsed Time (MET): 31903071
Image ID: 5561889
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: 18.3°
Center Longitude: 43.8° E
Resolution: 45 meters/pixel
Scale: The crater at lower left is about 26 km (16 mi.) in diameter
Incidence Angle: 28.2°
Emission Angle: 4.4°
Phase Angle: 32.4°
North is to the top right of the image.

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. MESSENGER acquired over 150,000 images and extensive other data sets. MESSENGER is capable of continuing orbital operations until early 2015.

For information regarding the use of images, see the MESSENGER image use policy.