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Last updated on April 20, 2014 at 5:20 EDT
Craters of the Ages
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Craters of the Ages

February 24, 2014
Release Date: February 21, 2014 Topics: NAC, Named Craters Date acquired: January 28, 2014 Image Mission Elapsed Time (MET): 33256970 Image ID: 5658155 Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS) Center Latitude: 31.1° Center Longitude: 326.6° E Resolution: 48 meters/pixel Scale: The crater to the lower left is about 22 km (14 mi.) in diameter Incidence Angle: 44.3° Emission Angle: 41.6° Phase Angle: 73.2° North is to the bottom right of the image. Of Interest: As we have seen before, the surface of Mercury is dominated by impact craters. One of the ways we know this process to be very long-lived is the state of preservation of a given crater: relatively young craters will have well preserved, intact rims, whereas older craters will look more subdued. This image, taken from a somewhat oblique viewing (or emission) angle, nicely shows the contrast in age between two craters to the northwest of Geddes crater. The crater to the top of the image has a sharper rim than the crater near the bottom. We can therefore confidently say that the crater at top formed more recently than its softened neighbor—and use similar relations to determine the relative ages of craters and basins across Mercury. This image was acquired as a targeted set of stereo images. Targeted stereo observations are acquired at resolutions much higher than that of the 200-meter/pixel stereo base map. These targets acquired with the NAC enable the detailed topography of Mercury's surface to be determined for a local area of interest. 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. During the first two years of orbital operations, MESSENGER acquired over 150,000 images and extensive other data sets. MESSENGER is capable of continuing orbital operations until early 2015. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington