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A Terminator Shot
Click on image to enlarge.
A Terminator Shot
Release Date: October 2, 2009
Topics: Mercury Flyby 3, NAC, Terminator Views



Date Acquired: September 29, 2009
Image Mission Elapsed Time (MET): 162744111
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Resolution: 410 meters/pixel (0.25 miles/pixel)
Scale: This image is about 420 kilometers (260 miles) from top to bottom
Spacecraft Altitude: 15,900 kilometers (9,900 miles)

Of Interest: As MESSENGER approached Mercury, the NAC acquired a high-resolution mosaic of the sunlit crescent planet that contained 62 images. To ensure that the entire sunlit portion of Mercury was covered in the mosaic, a few of the images, like the one here, have large areas of blackness. The terminator, the division between the dark night side and light dayside, runs through the middle of this NAC shot. Shadows are elongated in this image, as the craters catch the rays of an evening Sun. At the actual terminator location in this image, only the highest points of crater rims and inner peak rings are seen illuminated by sunlight. Such grazing lighting conditions can provide important information about the heights of geologic features on the surface.

Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington


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


   

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