With the sun low in the sky to the west, the interiors of craters are completely hidden in shadow and even the smallest surface features cast shadows. In this light, the cratered interior of the Caloris basin takes on a rough and formidable appearance, though its volcanic plains are actually smoother than much of the planet.

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 250-meter/pixel (820 feet/pixel) morphology base map or the 1-kilometer/pixel (0.6 miles/pixel) color base map. It is not possible to cover all of Mercury's surface at this high resolution during MESSENGER's one-year mission, but several areas of high scientific interest are generally imaged in this mode each week.

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.

Date acquired: July 25, 2011
Image Mission Elapsed Time (MET): 220117408
Image ID: 550483
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filter: 7 (748 nanometers)
Center Latitude: 26.83°
Center Longitude: 179.8° E
Resolution: 133 meters/pixel
Scale: The large crater is approximately 58 km (36 miles) in diameter
Incidence Angle: 88.5°
Emission Angle: 40.9°
Phase Angle: 129.4°

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.