The Inner Circle

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Caption:

Rachmaninoff is a spectacular double-ring basin on Mercury, and this color view is one of the highest resolution color image sets acquired of the basin's floor. Visible around the edges of the frame is a circle of mountains that make up Rachmaninoff's peak ring structure, which surrounds concentric troughs located on the on the basin floor. The color of the basin's floor inside the peak-ring differs from the darker material outside of it, as can also be seen in this previously posted color image .

This image was acquired as a high-resolution targeted color observation. Targeted color observations are images of a small area on Mercury's surface at resolutions higher than the 1-kilometer/pixel 8-color base map. During MESSENGER's one-year primary mission, hundreds of targeted color observations were obtained. During MESSENGER's extended mission, high-resolution targeted color observations are more rare, as the 3-color base map is covering Mercury's northern hemisphere with the highest-resolution color images that are possible.

Date acquired: July 31, 2012
Image Mission Elapsed Time (MET): 252265403, 252265399, 252265395
Image ID: 2305612, 2305611, 2305610
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filters: 9, 7, 6 (996, 748, 433 nanometers) in red, green, and blue
Center Latitude: 27.64°
Center Longitude: 57.58° E
Resolution: 149 meters/pixel
Scale: Rachmaninoff's inner ring is approximately 140 kilometers (87 miles) in diameter
Incidence Angle: 39.7°
Emission Angle: 19.2°
Phase Angle: 59.0°

Background Info:

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 acquired 88,746 images and extensive other data sets. MESSENGER is now in a year-long extended mission, during which plans call for the acquisition of more than 80,000 additional images to support MESSENGER's science goals.

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 .

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