In both the optical navigation images (PIA11244) and the full-planet
Wide Angle Camera (WAC) approach frame (PIA11247), a bright feature
is clearly visible in the northern portion of the crescent-shaped Mercury.
This NAC image resolves details of this bright feature, showing that it
surrounds a small crater about 30 kilometers (19 miles) in diameter, seen
nearly edge-on. Presumably, the bright material was ejected from this
small crater, which apparently formed relatively recently in Mercury’s
past, because Mercury’s surface materials tend to darken with time. The
brilliant ejecta are so bright compared with the neighboring surface that
Earth-based telescopic observations also detected this feature, despite
its being associated with such a small crater.
Date Acquired: October 6, 2008
Image Mission Elapsed Time (MET): 131766564
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Resolution: 410 meters/pixel (0.25 miles/pixel) in the lower right corner of the image
Scale: The bright crater is about 30 kilometers in diameter (19 miles)
Spacecraft Altitude: 16,000 kilometers (9,900 miles)
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.