MESSENGER: The Science Phase

[bystander]

Crater, Crater, Crater!
NASA JHU-APL CIW | MESSENGER | 2011 Jun 09

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This spectacular image includes three large craters, approximately 12 km, 30 km, and 70 km in diameter. The largest crater is the oldest of the three, with the other two superposed on top of it. The 30-km-diameter crater exhibits a very interesting and unusual central peak structure.

This image was acquired as part of MDIS's high-resolution surface morphology base map. The surface morphology base map will cover more than 90% of Mercury's surface with an average resolution of 250 meters/pixel (0.16 miles/pixel or 820 feet/pixel). Images acquired for the surface morphology base map typically have off-vertical Sun angles (i.e., high incidence angles) and visible shadows so as to reveal clearly the topographic form of geologic features.

Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

[bystander]

Verdi's Encore
NASA JHU-APL CIW | MESSENGER | 2011 Jun 10

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This view off the limb of Mercury provides a unique oblique view of the crater Verdi. Topographic variation can be seen along Mercury's limb. Limb images can be used to supplement topographic measurements made using MLA, occultations, and stereo imaging.

Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

[bystander]

March Madness
NASA JHU-APL CIW | MESSENGER | 2011 Jun 13

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This image, taken with the Narrow Angle Camera (NAC), shows March crater, named for the 15th century Valencian poet Ausiàs March. The faint striations across the wall terraces in the lower right portion of the image may have been caused by landsliding or by emplacement of ejecta from another impact outside the field of view.

This image was acquired as part of MDIS's high-resolution surface morphology base map. The surface morphology base map will cover more than 90% of Mercury's surface with an average resolution of 250 meters/pixel (0.16 miles/pixel or 820 feet/pixel). Images acquired for the surface morphology base map typically have off-vertical Sun angles (i.e., high incidence angles) and visible shadows so as to reveal clearly the topographic form of geologic features.

A Wrinkle Ridge in Time
NASA JHU-APL CIW | MESSENGER | 2011 Jun 14

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This image, taken with the Wide Angle Camera (WAC), shows a close-up of an unnamed crater. The wavy wrinkle ridges in the upper left formed after the crater was filled with lava. Once it cooled and solidified, the volcanic fill buckled as it subsided and contracted.

This image was acquired as part of MDIS's high-resolution surface morphology base map. The surface morphology base map will cover more than 90% of Mercury's surface with an average resolution of 250 meters/pixel (0.16 miles/pixel or 820 feet/pixel). Images acquired for the surface morphology base map typically have off-vertical Sun angles (i.e., high incidence angles) and visible shadows so as to reveal clearly the topographic form of geologic features.

Toc-crater and Fugue
NASA JHU-APL CIW | MESSENGER | 2011 Jun 15

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This image, taken with the MDIS Narrow Angle Camera (NAC), shows two named craters imaged by both MESSENGER and Mariner 10. At the bottom of the image are the double rings of Bach, a peak-ring basin named for the German composer J.S. Bach. The bright crater toward the top is Alencar, named for the Brazilian novelist José de Alencar; the central peak structure and terraced walls make it a good example of a complex crater.

This image was acquired as part of MDIS's high-resolution surface morphology base map. The surface morphology base map will cover more than 90% of Mercury's surface with an average resolution of 250 meters/pixel (0.16 miles/pixel or 820 feet/pixel). Images acquired for the surface morphology base map typically have off-vertical Sun angles (i.e., high incidence angles) and visible shadows so as to reveal clearly the topographic form of geologic features.

What Happens in Degas Stays in Degas
NASA JHU-APL CIW | MESSENGER | 2011 Jun 16

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This WAC image provides an extraordinary view of the crater Degas (pronounced duh-GAH), named for the French Impressionistic artist Edgar Degas. The crater's floor contains cracks that formed as the pool of impact melt cooled and shrank. The high-reflectance material on the walls and in the central portion of the crater probably has a composition distinct from that of the crater floor and surroundings. The illumination conditions and down-slope movement of eroded material exposing fresh rock also contribute to the bright appearance. A color image of part of Degas was featured in the June 16, 2011 NASA MESSENGER press conference.

This image was acquired as a high-resolution targeted observation. Targeted observations are images of a small area on Mercury's surface at resolutions much higher than the 250-meter/pixel (820 feet/pixel) morphology base map or the 1-kilometer/pixel (0.6 miles/pixel) color base map. It is not possible to cover all of Mercury's surface at this high resolution during MESSENGER's one-year mission, but several areas of high scientific interest are generally imaged in this mode each week.

A Swiftly Non-Tilting Planet
NASA JHU-APL CIW | MESSENGER | 2011 Jun 17

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This image was taken with the Wide Angle Camera (WAC) and shows part of Mercury's southern hemisphere, taken from the far south, looking north. (The companion image, showing the rest of the southern hemisphere, can be found here.) Unlike Earth (referred to in the title of Madeleine L'Engle's book A Swiftly Tilting Planet), Mercury has a very small axial tilt of only about .02 degrees--the smallest in the Solar System. As a result, Mercury has no seasons.

This image was acquired as part of MDIS's limb imaging campaign. Once per week, MDIS captures images of Mercury's limb, with an emphasis on imaging the southern hemisphere limb. These limb images provide information about Mercury's shape and complement measurements of topography made by the Mercury Laser Altimeter (MLA) of Mercury's northern hemisphere.

Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington