Unnamed Impact Crater Southeast of Stieglizt Crater

This small, bright crater is located in the northern plains of Mercury, southeast of the crater Stieglitz. Though it is one of many craters in the 2-5 km size range in this image, most of the others are clearly members of crater chains, created in quick succession during secondary impacts. The crater in the western portion of the image stands out from its surroundings both due to its morphology and its freshness.

This image was acquired as part of MDIS's minimum-phase-angle color campaign. Near the north polar region, the incidence angle (measured from the vertical) is always fairly high because the Sun is low on the horizon. The minimum-phase-angle color campaign acquires images under conditions that minimize the shadows in an image by viewing the surface as nearly as possible from the same direction as the Sun's illumination, which minimizes the phase angle. Images are acquired through five of the WAC's narrow-band color filters, for regions north of 60° N, at an average resolution of 500 meters/pixel. The minimum-phase-angle color campaign began in March 2013.

Date acquired: July 04, 2014
Image Mission Elapsed Time (MET): 46773193, 46773184, 46773190
Image ID: 6618773, 6618770, 6618772
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filters: 9, 7, 6 (996, 748, 433 nanometers) in red, green, and blue
Center Latitude: 68.82°
Center Longitude: 71.79° E
Resolution: 273 meters/pixel
Scale: This image is roughly 225 km (140 mi.) from corner to corner.
Incidence Angle: 73.9°
Emission Angle: 45.8°
Phase Angle: 28.0°

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

Stieglitz Crater

At the bottom of this image is a part of the rim of crater Stieglitz. Alfred Stieglitz was an American photographer who lived from 1864 to 1946. His wife, painter Georgia O'Keeffe, is honored by a crater on the planet Venus.

Date acquired: July 21, 2011
Image Mission Elapsed Time (MET): 219733996
Image ID: 532053
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filter: 7 (748 nanometers)
Center Latitude: 74.73°
Center Longitude: 66.86° E
Resolution: 108 meters/pixel
Scale: The crater at the top of the image is about 26 km (16 mi.) in diameter.
Incidence Angle: 78.3°
Emission Angle: 0.2°
Phase Angle: 78.3°

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

Radar-Bright Deposits in Mercury's North Polar Region

MESSENGER's highly eccentric orbit, which passes low over Mercury's north polar region, enables higher-resolution views of Mercury's surface in the north than in the south. Shown here is a subset of this image; the large 100-km diameter crater in the center is located at 72.5° N, 67.4° E and was recently named Stieglitz, for the American photographer Alfred Stieglitz. Of particular note are the craters hosting radar-bright features at low latitudes, extending southward to 67° N, and the many small craters that host radar-bright deposits. Low-latitude and small craters provide thermally challenging environments for water ice to persist. A thin (few tens of centimeters thick) layer of insulation is likely required to cover and to lower the temperature of these deposits if they are water ice. However, the smallest craters and the lowest-latitude locations may prove a challenge for water ice stability over extended periods of geologic time even with such cover.

Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)

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

Note: For a similar image showing a wide-area map of the north polar region, see PIA15530: Radar-bright Deposits near Mercury's North Pole.