Stieglitz Crater Hosts Radar Bright Materials in Shadowed Areas

Summary: Stieglitz Crater hosts radar bright materials in shadowed areas on the crater’s north-facing walls and at its interior floor’s midpoint.

Image acquired via NASA’s MESSENGER spacecraft’s Mercury Dual Imaging System (MDIS) shows Stieglitz Crater and its northern neighbor, Gaudí Crater, as two large craters (upper center) on smooth plains of Borealis Planitia (Northern Plain) in Mercury’s high northern latitudes; MDIS monochrome base map has been color-coded by elevation (blue=lower elevation; red=high elevation; green, yellow=northern rise of about 1.5 kilometers [1 mile]); NASA ID PIA16536; image addition date 2012-11-14; image credit NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington: May be used for any purpose without prior permission, via NASA JPL Photojournal

Stieglitz Crater hosts radar bright materials in shadowed areas that are located at the midpoint of the crater’s interior floor and on north-facing walls of the crater’s southern side.

Stieglitz Crater is a crater on Mercury, the Solar System planet that orbits closest to the sun. Stieglitz occurs within Borealis Planitia (Northern Plain), the Mercurial north polar region’s smooth plains.

Stieglitz is centered at 72.54 degrees north latitude, 292.37 degrees west longitude, according to the Gazetteer of Planetary Nomenclature. The northern hemisphere crater’s northernmost and southernmost latitudes occur at 73.63 degrees north and 71.44 degrees north, respectively. The polar region crater obtains its easternmost and westernmost longitudes at 288.7 degrees west and 296.03 degrees west, respectively. Stieglitz Crater’s diameter measures 100 kilometers.

Gaudí Crater is Stieglitz Crater’s nearest named neighbor in Borealis Planitia. Stieglitz lies to the south of Gaudí.

Gaudí is centered at 76.9 degrees north latitude, 290.84 degrees west longitude. It registers northernmost and southernmost latitudes of 77.85 degrees north and 75.96 degrees north, respectively. It records easternmost and westernmost longitudes of 286.67 degrees west and 295.01 degrees west, respectively. Gaudí Crater has a diameter of 81 kilometers.

Gaudí and Stieglitz number among the plethora of craters hosting radar-bright features in Mercury’s north polar region. Planetary scientist Nancy L. Chabot and six co-authors, representing a collaboration of researchers from Maryland’s Johns Hopkins University Applied Physics Laboratory (JHUAPL), the National Astronomy and Ionosophere Center at Puerto Rico’s Arecibo Observatory and Washington DC’s Carnegie Institution, reported on “Craters Hosting Radar-Bright Deposits in Mercury’s North Polar Region” at the 43rd Lunar and Planetary Science Conference, held Monday, March 19, to Friday, March 23, 2012, in The Woodlands, east central Texas.

The Mercury Dual Imaging System (MDIS) carried by the National Aeronautics and Space Administration’s (NASA) robotic spacecraft MESSENGER (Mercury Surface, Space Environment, Geochemistry, and Ranging) imaged Mercury’s surface, with an average resolution of 250 meters per pixel. MESSENGER’s highly eccentric orbit exhibited a minimum altitude of approximately 200 kilometers over the north polar region and a maximum altitude of approximately 15, 200 kilometers over the south polar region.

Two base maps presented the same terrain under different illumination conditions. A monochrome map emphasized surface morphology. A color map enabled the determination of color characteristics. Averaging the two base maps captured the locations remaining in shadow in both maps. A comparison with the highest resolution radar images obtained from Puerto Rico’s Arecibo Observatory yielded congruity between radar-bright and shadowed locations.

Mapping of all craters with diameters equal to or greater than 10 kilometers revealed the prevalence of radar-bright features in craters near Mercury’s north pole. Craters lacking radar-bright features stood out as exceptions.

Both Gaudí Crater and Stieglitz Crater exhibit radar-bright features that coincide with locations identified as shadowed in the MDIS data. The radar-bright, shadowed locations occur along the north-facing walls of their southern sides. Radar-bright, shadowed areas appear in the central peak formation on Stieglitz Crater’s interior floor. Easily half a dozen radar-bright, shadowed areas dot Gaudí Crater’s interior floor.

Chabot and her six co-researchers reference the hypothesis of Mercury’s permanent, polar region cold traps put forth in papers in the October 23, 1992, issue of Science by Martin Slade of NASA’s Jet Propulsion Laboratory (JPL) and Bryan Butler and Duane Muhleman of the California Institute of Technology’s (Caltech) Division of Geological and Planetary Sciences and by Slade with John Harmon of Arecibo, Puerto Rico’s National Astronomy and Ionosphere Center. Slade, Butler and Muhleman collected their data from radar observations conducted Aug. 8 and Aug. 23, 1991, via transmitting by NASA JPL’s Goldstone 70-meter (230-foot) antenna in the Mojave Desert, southeastern California, and receiving by the National Radio Astronomy Observatory’s Very Large Array (VLA) in Socorro, south central New Mexico. Random-code delay-Doppler mapping obtained by Harmon at Arecibo over 28 dates supported the hypothesis of cold, permanently shadowed, large craters in Mercury’s north polar region as stable water ice traps.

The takeaways for Stieglitz Crater’s hosting of radar-bright materials in shadowed areas are that maps obtained via NASA’s robotic MESSENGER spacecraft’s Mercury Dual Imaging System (MDIS) reveal the prevalent coincidence of radar-bright materials with shadowed areas in craters with diameters of 10 or more kilometers in Mercury’s north polar region and that the results are consistent with a water-ice hypothesis of trapped water ice in cold, persistently shadowed sites.

Image obtained Aug. 27, 2012, by NASA’s robotic MESSENGER spacecraft shows Stieglitz Crater’s central peak, which hosts radar-bright materials; NASA ID PIA16420; image addition date 2012-10-08; image credit NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington: May be used for any purpose without prior permission, via NASA JPL Photojournal

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

Image acquired via NASA’s MESSENGER spacecraft’s Mercury Dual Imaging System (MDIS) shows Stieglitz Crater and its northern neighbor, Gaudí Crater, as two large craters (upper center) on smooth plains of Borealis Planitia (Northern Plain) in Mercury’s high northern latitudes; MDIS monochrome base map has been color-coded by elevation (blue=lower elevation; red=high elevation; green, yellow=northern rise of about 1.5 kilometers [1 mile]); NASA ID PIA16536; image addition date 2012-11-14; image credit NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington: May be used for any purpose without prior permission, via NASA JPL Photojournal @ https://photojournal.jpl.nasa.gov/catalog/PIA16536

Image obtained Aug. 27, 2012, by NASA’s robotic MESSENGER spacecraft shows Stieglitz Crater’s central peak, which hosts radar-bright materials; NASA ID PIA16420; image addition date 2012-10-08; image credit NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington: May be used for any purpose without prior permission, via NASA JPL Photojournal @ https://photojournal.jpl.nasa.gov/catalog/PIA16420

For further information:

Chabot, Nancy L.; Carolyn M. Ernst; John K. Harmon; Scott L. Murchie; Sean C. Solomon; David T. Blewett; and Brett W. Denevi. “Craters Hosting Radar-Bright Deposits in Mercury’s North Polar Region.” 43 Lunar and Planetary Science Conference, 2012.
Available @ https://www.lpi.usra.edu/meetings/lpsc2012/pdf/1476.pdf

Grego, Peter. Venus and Mercury, and How to Observe Them. Astronomers’ Observing Guides. New York NY: Springer Science+Business Media, 2008.

Harmon, John K.; and Martin A. Slade “Radar Mapping of Mercury: Full-Disk Images and Polar Anomalies.” Science, new series vol. 258, issue 5082 (Oct. 23, 1992): 640-643.
Available via AAAS (American Association for the Advancement of Science) @ https://science.sciencemag.org/content/258/5082/640
Available via JSTOR @ https://www.jstor.org/stable/2880195

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Borealis Planitia.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > The Moon. Last updated April 17, 2018.
Available @ https://planetarynames.wr.usgs.gov/Feature/823

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Gaudí.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > The Moon. Last updated Aug. 6, 2012.
Available @ https://planetarynames.wr.usgs.gov/Feature/15021

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Stieglitz.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > The Moon. Last updated Feb. 27, 2012.
Available @ https://planetarynames.wr.usgs.gov/Feature/14928

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Target: Mercury.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > Mercury.
Available @ https://planetarynames.wr.usgs.gov/Page/MERCURY/target

Jenner, Lynn, page ed. “Mountains of Darkness.” NASA > Mission Pages > MESSENGER > Multimedia. Page last updated Oct. 8, 2012.
Available @ https://www.nasa.gov/mission_pages/messenger/multimedia/messenger_orbit_image20121008_1.html

Kreslavsky, M.A.; J.W. Head; G.A. Neumann; M.T. Zuber; and D.E. Smith. “Features of the Northern Smooth Plains of Mercury Revealed by Detrended MLA Topography: Comparison With the Moon.” 47th Lunar and Planetary Science Conference, March 21-25, 2016: Abstract #1333.
Available via USRA-Houston @ https://www.hou.usra.edu/meetings/lpsc2016/pdf/1333.pdf

Marriner, Derdriu. “Stieglitz Crater Honors American Photographer Alfred Stieglitz.” Earth and Space News. Wednesday, July 10, 2013.
Available @ https://earth-and-space-news.blogspot.com/2013/07/stieglitz-crater-honors-american.html

NASA Jet Propulsion Laboratory. “PIA16536: Running Up That Hill.” NASA Jet Propulsion Laboratory Photojournal > Catalog. Image added 2012-11-14.
Available @ https://photojournal.jpl.nasa.gov/catalog/PIA16536

NASA Messenger. “Image of Mercury: Close-up of Craters Hosting Radar-Bright Deposits.” SpaceRef > Solar System > Mercury. March 26, 2012.
Available @ http://spaceref.com/news/viewsr.html?pid=40381

Paige, David A.; Stephen E. Wood; and Ashwin R. Vasavada. “The Thermal Stability of Water Ice at the Poles of Mercury.” Science, new series vol. 258, issue 5082 (Oct. 23, 1992): 643-646.
Available via AAAS (American Association for the Advancement of Science) @ https://science.sciencemag.org/content/258/5082/643
Available via UCLA Diviner @ http://luna1.diviner.ucla.edu/~dap/pubs/012.pdf

Slade, Martin A.; Bryan J. Butler; and Duane O. Muhleman. “Mercury Radar Imaging: Evidence for Polar Ice.” Science, new series vol. 258, issue 5082 (Oct. 23, 1992): 635-640.
Available via AAAS (American Association for the Advancement of Science) @ https://science.sciencemag.org/content/258/5082/635
Available via JSTOR @ https://www.jstor.org/stable/2880194

Talbert, Tricia, ed. “MESSENGER Finds New Evidence for Water Ice at Mercury’s Poles.” NASA > Mission Pages > MESSENGER > Media. Nov. 29, 2012.
Available @ https://www.nasa.gov/mission_pages/messenger/media/PressConf20121129.html