One week ago, on January 14, 2008, MESSENGER passed 200 kilometers (124 miles) above the surface of Mercury and snapped the first pictures of a side of Mercury not previously seen by a spacecraft. A new 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.
This image is just one in a planned sequence of 42 images acquired by the Narrow Angle Camera 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. During the flyby, MDIS took more than 1,200 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).
Additional information and features from MESSENGER's first flyby of Mercury are online at http://messenger.jhuapl.edu/mer_flyby1.html.
MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) is a NASA-sponsored scientific investigation of the planet Mercury and the first space mission designed to orbit the planet closest to the Sun. The MESSENGER spacecraft launched on August 3, 2004, and after flybys of Earth, Venus, and Mercury will start a yearlong study of its target planet in March 2011. Dr. Sean C. Solomon, of the Carnegie Institution of Washington, leads the mission as Principal Investigator. The Johns Hopkins University Applied Physics Laboratory built and operates the MESSENGER spacecraft and manages this Discovery-class mission for NASA.
The above post is reprinted from materials provided by Johns Hopkins University Applied Physics Laboratory. Note: Content may be edited for style and length.
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