Once per week, MDIS captures images of Mercury's limb (the edge of the sunlit planet with space), with an emphasis on imaging the southern hemisphere limb. An example of one of those limb images is shown here. The spacecraft was high above Mercury's south polar region when capturing this image. However, even when the spacecraft is at its highest altitude above Mercury, a single WAC image cannot capture the entire limb of Mercury. Consequently, two images are taken and mosaicked together to image Mercury's entire limb. These limb images will provide information about Mercury's shape and will complement measurements of topography made by the Mercury Laser Altimeter (MLA) of Mercury's northern hemisphere. Read about MDIS's other imaging campaigns in this featured story.

On March 17, 2011 (March 18, 2011, UTC), MESSENGER became the first spacecraft ever to orbit the planet Mercury. The mission is currently in its commissioning phase, during which spacecraft and instrument performance are verified through a series of specially designed checkout activities. In the course of the one-year primary mission, the spacecraft's seven scientific instruments and radio science investigation will unravel the history and evolution of the Solar System's innermost planet. Visit the Why Mercury? section of this website to learn more about the science questions that the MESSENGER mission has set out to answer.

Date acquired: April 24, 2011
Image Mission Elapsed Time (MET): 212176084
Image ID: 171644
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filter: 7 (748 nanometers)
Center Latitude: -58.57°
Center Longitude: 308.1° E
Scale: Mercury's radius in 2440 kilometers

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.