Last updated on April 18, 2014 at 1:21 EDT
At the Edge of a World
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At the Edge of a World

October 28, 2008
  • Date Acquired: October 6, 2008
  • Image Mission Elapsed Time (MET): 131766475
  • Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
  • Resolution: 420 meters/pixel (0.26 miles/pixel) at the right side of the image
  • Scale: The right side of this image is about 430 kilometers (270 miles) tall
  • Spacecraft Altitude: 16,400 kilometers (10,200 miles)

Of Interest: Taken as MESSENGER approached Mercury, this NAC image shows a portion of the sunlit crescent-shaped planet with the edge of Mercury against the blackness of space. A large region of smooth plains can be seen in the upper portion of this image, extending to the north, into an image previously released on October 8. To the south, near the edge of the planet, a lengthy cliff face is visible running off the bottom of the image and onto an image released on October 17. With this overlap, these three NAC images can be nicely mosaicked together and are part of a larger 44-image mosaic set. Particularly prominent in the image here is a crater near the bottom of the frame with numerous associated chains of small secondary craters. The secondary craters, which are especially visible on the southern portion of the smooth plains, were formed when material was thrown out onto the surrounding surface during the impact event that created the large crater. Thus, this large crater was formed after the creation of the neighboring smooth plains.