One week ago, on January 14, 2008, the MESSENGER spacecraft passed 200
kilometers (124 miles) above the surface of Mercury and snapped the first
pictures of a side of Mercury not previously seen by spacecraft. This
image shows that previously unseen side, with a view looking toward
Mercury's south pole. The southern limb of the planet can be seen in the
bottom right of the image. The bottom left of the image shows the
transition from the sunlit, day side of Mercury to the dark, night side
of the planet, a transition line known as the terminator. In the region
near the terminator, the sun shines on the surface at a low angle, causing
the rims of craters and other elevated surface features to cast long
shadows, accentuating height differences in the image. A raised crater rim
that is just catching the last glint of sunlight can be seen prominently
in this terminator region.
This image is just one in a planned sequence of 42 images acquired by the
Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS). From
these 42 images, the MESSENGER team is creating a high-resolution mosaic
image of this previously unseen portion of Mercury. In total during the
flyby, MDIS took more than 1200 images, which are being combined to create
multiple mosaics with different resolutions and of different portions of
the planet. The creation of high-resolution mosaic images will enable a
global view of Mercury's surface and will be used to understand the
geologic processes that made Mercury the planet we see today.
This image was acquired about 98 minutes after MESSENGER's closest
approach to Mercury, when the spacecraft was at a distance of about 33,000
kilometers (21,000 miles).
Mission Elapsed Time (MET) of image: 108830711
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.
