Jingpo Lacus Glints During Cassini Orbiter’s Titan Flyby July 8, 2009

Summary: Jingpo Lacus glints during Cassini Orbiter’s Titan flyby July 8, 2009, according to Cassini’s Visible and Infrared Mapping Spectrometer (VIMS).

Cassini Orbiter’s Visible and Infrared Mapping Spectrometer’s (VIMS) July 8, 2009, image capture of sunlight reflected from the north polar region’s Jingpo Lacus confirms liquid presence in Titan’s northern hemisphere; NASA ID PIA12481; image added Dec. 17, 2009; image credit NASA/JPL/University of Arizona/DLR: May be used for any purpose without prior permission, via NASA JPL Photojournal

Jingpo Lacus glints during Cassini Orbiter’s Titan flyby July 8, 2009, according to an image obtained by the spacecraft’s Visible and Infrared Mapping Spectrometer (VIMS).

The glint typifies a specular reflection, which is a reflection that has the properties of a mirror. A specular reflection occurs as a mirror-like reflection of waves, all at the same angle, from a smooth surface.

Cassini scientists identified the glinting location on Titan by examining radar and near-infrared light images obtained from 2006 to 2008. The glint seemed to originate near the western shores of Kraken Mare, the largest know liquid body on Titan. The scientists tracked the glint’s location to a part of Jingpo Lacus near 71 degrees north latitude, 337 degrees west longitude.

Jingpo Lacus is a north polar region lake on Titan, the largest Saturnian moon. The Titanean lake encompasses an area of 20,800 square kilometers (8,000 square miles), according to the National Aeronautics and Space Administration (NASA) Jet Propulsion Laboratory’s (JPL) Photojournal website.

The image of glinting Jingpo Lacus was obtained approximately 33 days before Saturn’s spring equinox. The CICLOPS (Cassini Imaging Central Laboratory for Operations) website, which officially sources Cassini images of the Saturnian system, details the Saturnian vernal (Latin: vernalis, “of or pertaining to spring”) equinox as taking place Tuesday, Aug. 11, at 00:15 Coordinated Universal Time (Monday, Aug. 10, at 8:15 p.m. Eastern Daylight Time). Saturn’s orbital period of approximately 29 Earth years explains the occurrence of its spring equinox approximately every 15 Earth years.

NASA’s Cassini Orbiter detected the sunlight reflected off Jingpo Lacus during the spacecraft’s 59th flyby of Titan. The image was obtained at an approximate distance of 200,000 kilometers (120,000 miles). Cassini’s Visual and Infrared Mapping Spectrometer created the image via light wavelengths in the 5 micron range.

The image resolution detailed approximately 100 kilometers (60 miles) per pixel. The German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) in Berlin, Germany, and the University of Arizona in Tucson collaborated in the image’s processing.

Dr. Katrin Stephan was “. . . the first to see the glint on July 10th,” according to JPL media relations specialist and science writer Jia-Rui Cook’s Dec. 17, 2009, post on NASA’s Cassini Mission News webpages. Dr. Stephan, who is an associate member of the VIMS team, processed the initial image.

“I was instantly excited because the glint reminded me of an image of our own planet taken from orbit around Earth, showing a reflection of sunlight on an ocean,” Stephan recalled. “But we also had to do more work to make sure the glint we were seeing wasn’t lightning or an erupting volcano.”

The NASA JPL Photojournal website’s Dec. 17, 2009, posting announced that the glint “. . . confirmed the presence of liquid in the moon’s northern hemisphere, where lakes are more numerous and larger than those in the southern hemisphere.”

Cassini co-investigator Ralf Jaumann noted the glint finding as revelatory of the stability of Kraken Mare’s shoreline over the past three years and of an ongoing Titanean cycle of surfacing liquids.

“These results remind us how unique Titan is in the solar system,” Jaumann observed for Jia-Rui Cook’s Dec. 17, 2009, post. “But they also show us that liquid has a universal power to shape geological surfaces in the same way, no matter what the liquid is.”

Cassini project scientist Robert (Bob) Pappalardo considered: “This one image communicates so much about Titan -- thick atmosphere, surface lakes and an otherworldliness.” He described the image as “. . . an unsettling combination of strangeness yet similarity to Earth. This picture is one of Cassini’s iconic images.”

The takeaways for glinting Jingpo Lacus during Cassini Orbiter’s Titan flyby July 8, 2009, are that the spacecraft’s Visible and Infrared Mapping Spectrometer (VIMS) obtained the image approximately 33 days before Saturn’s spring equinox; that the image captured a specular reflection, in which light waves reflected, mirror-like, from the smooth, mirror-like surface of Jingpo Lacus; and that the image confirmed a liquid presence in Titan’s northern hemisphere.

Cassini false-color mosaic shows Jingpo Lacus (blue; lower center left) in Saturnian moon Titan’s north polar region; NASA ID PIA10008; image addition date Oct. 11, 2007; image credit NASA/JPL-Caltech/USGS: May be used for any purpose without prior permission, via NASA JPL Photojournal @ https://photojournal.jpl.nasa.gov/catalog/?IDNumber=PIA10008

Acknowledgment

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

Image credits:

Cassini Orbiter’s Visible and Infrared Mapping Spectrometer’s (VIMS) July 8, 2009, image capture of sunlight reflected from the north polar region’s Jingpo Lacus confirms liquid presence in Titan’s northern hemisphere; NASA ID PIA12481; image added Dec. 17, 2009; image credit NASA/JPL/University of Arizona/DLR: May be used for any purpose without prior permission, via NASA JPL Photojournal @ https://photojournal.jpl.nasa.gov/catalog/PIA12481;
Generally not subject to copyright in the United States; may use this material for educational or informational purposes, including photo collections, textbooks, public exhibits, computer graphical simulations and Internet Web pages; general permission extends to personal Web pages, via NASA Image and Video Library @ https://images.nasa.gov/details-PIA12481

Cassini false-color mosaic shows Jingpo Lacus (blue; lower center left) in Saturnian moon Titan’s north polar region; NASA ID PIA10008; image addition date Oct. 11, 2007; image credit NASA/JPL-Caltech/USGS: May be used for any purpose without prior permission, via NASA JPL Photojournal @ https://photojournal.jpl.nasa.gov/catalog/?IDNumber=PIA10008;
Public Domain, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:PIA10008_Seas_and_Lakes_on_Titan_full_size.jpg

For further information:

Brown, Robert H.; Jean-Pierre Lebreton; and J. Hunter Waite, eds. Titan From Cassini Huygens. New York NY: Springer Science+Business Media B.V., 2009.

CICLOPS Cassini Imaging Central Laboratory for Operations. “Rev116: Aug 3-Aug 19 ’09.” CICLOPS > Newsroom.
Available @ http://ciclops.org/view/5751/Rev116

Cook, Jia-Rui C. “Sunlight Glint Confirms Liquid in Titan Lake Zone.” NASA > Mission Pages > Current Missions > Cassini-Huygens Mission to Saturn. Dec. 17, 2009.
Available @ https://www.nasa.gov/mission_pages/cassini/whycassini/cassini20091217.html

ESA European Space Agency. “Titan -- From Discovery to Encounter.” European Space Agency Science and Technology > Conferences.
Available @ https://sci.esa.int/web/conferences/-/35018-titan-from-discovery-to-encounter-conference-presentations

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Categories (Themes) for Naming Features on Planets and Satellites.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Documentation > Surface Feature Categories.
Available @ https://planetarynames.wr.usgs.gov/Page/Categories

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Jingpo Lacus.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > Saturn > Titan. Last updated March 29, 2010.
Available @ https://planetarynames.wr.usgs.gov/Feature/14655

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

Lakdawalla, Emily. “Cassini VIMS Sees the Long-Awaited Glint Off a Titan Lake.” The Planetary Society > Blogs. Dec. 17, 2009.
Available @ https://www.planetary.org/blogs/emily-lakdawalla/2009/2267.html

Lavoie, Sue, site mgr. “PIA10008: Reflection of Sunlight Off Titan Lake.” NASA Jet Propulsion Laboratory Photojournal > Catalog. Image addition date: 2007-10-11.
Available @ https://photojournal.jpl.nasa.gov/catalog/PIA12481

Lavoie, Sue, site mgr. “PIA12481: Titan’s North Polar Region.” NASA Jet Propulsion Laboratory Photojournal > Catalog. Image addition date: 2009-12-7.
Available @ https://photojournal.jpl.nasa.gov/catalog/PIA12481

Levy, David H. Skywatching. Revised and updated. San Francisco CA: Fog City Press, 1994.

Marriner, Derdriu. “Christiaan Huygens Discovered Saturnian Satellite Titan March 25, 1655.” Earth and Space News. Wednesday, March 28, 2012.
Available @ https://earth-and-space-news.blogspot.com/2014/03/christiaan-huygens-discovered-saturnian.html

Marriner, Derdriu. “Visible and Infrared Mapping Spectrometer VIMS Shows Titanean Surface.” Earth and Space News. Wednesday, March 30, 2011.
Available @ https://earth-and-space-news.blogspot.com/2012/03/visible-and-infrared-mapping.html

U.S. Geological Survey Astrogeology Science Center. “New Lacus Name on Titan.” USGS Astrogeology Science Center > News. March 29, 2010.
Available @ https://astrogeology.usgs.gov/news/nomenclature/new-lacus-name-on-titan

Watanabe, Susan, page ed. “The Rite of Spring.” NASA > Mission Pages > Current Missions > Cassini-Huygens Mission to Saturn. Sept. 21, 2009.
Available @ https://www.nasa.gov/mission_pages/cassini/multimedia/pia11667.html

The Red Planet’s Gill Crater Lies in Ancient Arabia Terra

Summary: The Red Planet’s Gill Crater lies in ancient Arabia Terra, a battered, upland region primarily occupying the Martian northern hemisphere.

Detail of Arabia Quadrangle, MC-12, shows Gill Crater and its closest, named neighbors in the Martian northern hemisphere’s portion of ancient Arabia Terra: U.S. Geological Survey Astrogeology Science Team, Public Domain, via IAU Working Group for Planetary System Nomenclature (WGPSN) / USGS Astrogeology Science Center

The Red Planet’s Gill Crater lies in ancient Arabia Terra, a densely-cratered upland region primarily located in the Martian northern hemisphere.

Gill Crater is centered at 15.76 degrees north latitude, 5.55 degrees east longitude, according to the International Astronomical Union’s (IAU) Gazetteer of Planetary Nomenclature. The northern hemisphere impact crater finds its northernmost and southernmost latitudes at 16.46 degrees north and 15.06 degrees north, respectively. It sets its easternmost and westernmost longitudes at 6.28 degrees east and 4.82 degrees east, respectively. Gill Crater’s diameter measures 83.17 kilometers.

Gill Crater honors British astronomer Sir David Gill (June 12, 1843-Jan. 24, 1914). The IAU approved Gill as the Martian impact crater’s official name in 1973, during the organization’s XVth (15th) General Assembly, held in Sydney, Australia, from Tuesday, Aug. 21, to Thursday, Aug. 30.

Gill Crater appears on the Arabia quadrangle, one of 30 cartographic quadrangles of the Martian surface devised by the U.S. Geological Survey’s Astrogeology Science Program. The Arabia quadrangle, which numbers as Mars Chart 12 (MC-12) in the series, covers 0 degrees to 30 degrees north latitude and 0 degrees to 45 degrees east longitude.

Arabia Terra comprises the northern extent of the Martian southern highlands. The Martian northern lowlands lie to the north of Arabia Terra.

Arabia Terra is centered at 21.25 degrees north latitude, 5.72 degrees east longitude. The topographically battered region records its northernmost and southernmost latitudes at 45.36 degrees north and minus 18.07 degrees south, respectively. It registers easternmost and westernmost longitudes of 49.44 degrees east and minus 29.69 degrees west, respectively. At its longest extent, Arabia Terra spans 4,851.74 kilometers.

Capen Crater appears as Gill Crater’s closest named neighbor on the Arabia quadrangle. Capen Crater resides to the southeast of Gill.

Capen Crater is centered at 6.58 degrees north latitude, 14.31 degrees east longitude. It confines its northernmost and southernmost latitudes to 7.16 degrees north and 6 degrees north, respectively. It restricts its easternmost and westernmost longitudes to 14.9 degrees east and 13.73 degrees east, respectively. Capen Crater has a diminutive diameter of 6.58 kilometers.

Capen Crater honors American astronomer Charles F. “Chick” Capen Jr (Jan. 1, 1926-May 28, 1986). The IAU approved Capen as the Martian impact crater’s official name on Jan. 2, 2008.

Henry Crater occurs as Gill Crater’s second closest, named southeastern neighbor on the Arabia quadrangle. Henry Crater lies to the northeast of Capen Crater.

Henry Crater is centered at 10.79 degrees north latitude, 23.45 degrees east longitude. The centrally mounded, large impact crater obtains its northernmost and southernmost latitudes at 12.2 degrees north and 9.38 degrees north, respectively. Its easternmost and westernmost longitudes occur at 24.89 degrees east and 22.01 degrees east, respectively. Henry Crater has a diameter of 10.79 kilometers.

Henry Crater honors French asteroid-hunting brothers Paul-Pierre Henry (Aug. 21, 1848-Jan. 4, 1905) and Prosper-Mathieu Henry (Dec. 10, 1849-July 25, 1903). Approval of Henry as the Martian impact crater’s official name occurred in 1973.

Maggini Crater occurs as Gill Crater’s closest, named northeastern neighbor on the Arabia quadrangle. The wrinkle-ridged crater is located in northwestern Arabia Terra.

Maggini Crater is centered at 27.78 degrees south latitude, 9.5 degrees east longitude. It posts northernmost and southernmost latitudes of 28.96 degrees north and 26.61 degrees north, respectively. It marks its easternmost and westernmost longitudes at 10.83 degrees east and 8.17 degrees east, respectively. Maggini Crater’s diameter measures 27.78 kilometers.

Maggini Crater honors Italian astronomer Mentore Maggini (Feb. 6, 1890-May 8, 1941). The IAU approved Maggini as the Martian impact crater’s official name in 1973.

Pasteur Crater’s location qualifies it as Gill Crater’s second closest, named northeastern neighbor. The duney crater lies to the southeast of Maggini Crater and to the north-northeast of Henry Crater.

Pasteur Crater is centered at 19.31 degrees north latitude, 24.62 degrees east longitude. Its northernmost and southernmost latitudes reach 20.29 degrees north and 18.33 degrees north, respectively. Its easternmost and westernmost longitudes extend to 25.66 degrees east and 23.58 degrees east, respectively. Pasteur Crater’s diameter spans 116.15 kilometers.

Pasteur Crater honors French chemist and microbiologist Louis Pasteur (Dec. 27, 1822-Sept. 28, 1895). Approval of Pasteur as the Martian impact crater’s official name was granted in 1973.

The takeaways for Gill Crater’s occurrence in ancient Arabia Terra are that the Martian impact crater resides in an impact-battered region in the Martian northern hemisphere; that the U.S. Geological Survey mapped Arabia Terra in the Arabia quadrangle, the 12th of the scientific agency’s 30 cartographic quadrangles of the Martian surface; that Capen Crater and Henry Crater occur as Gill Crater’s closest, named southeastern neighbors; and that Maggini Crater and Pasteur Crater qualify as Gill Crater’s closest, named northeastern neighbors.

Gill Crater (center left; crater label inserted) appears in Mars digital-image mosaic merged with color of MC-12 quadrangle of Martian Arabia Terra region; NASA ID PIA00172; image addition date 1998-06-05; image credit NASA/JPL/USGS: 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:

Detail of Arabia Quadrangle, MC-12, shows Gill Crater and its closest, named neighbors in the Martian northern hemisphere’s portion of ancient Arabia Terra: U.S. Geological Survey Astrogeology Science Team, Public Domain, via IAU Working Group for Planetary System Nomenclature (WGPSN) / USGS Astrogeology Science Center @ https://planetarynames.wr.usgs.gov/images/mc12_2014.pdf

Gill Crater (center) appears in detail of Mars digital-image mosaic merged with color of MC-12 quadrangle of Martian Arabia Terra region; NASA ID PIA00172; image addition date 1998-06-05; image credit NASA/JPL/USGS: May be used for any purpose without prior permission, via NASA JPL Photojournal @ https://photojournal.jpl.nasa.gov/catalog/pia00172

For further information:

Contopoulos, G. (George); and A. (Arnost) Jappel, eds. XVth General Assembly Transactions of the IAU Vol. XV B Proceedings of the 15th General Assembly and Extraordinary General Assembly Sydney, Australia, August 21-30, 1973. Cambridge UK: Association of Universities for Research in Astronomy, Jan. 1, 1974.
Available via IAU @ https://www.iau.org/publications/iau/transactions_b/

Grego, Peter. Mars and How to Observe It. Astronomers’ Observing Guides. New York NY: Springer Science+Business Media, 2012.

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Arabia Terra.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > Mars. Last updated Oct. 1, 2006.
Available @ https://planetarynames.wr.usgs.gov/Feature/335

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Capen.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > Mars. Last updated Nov. 17, 2010.
Available @ https://planetarynames.wr.usgs.gov/Feature/14327

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Gill.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > Mars. Last updated Nov. 17, 2010.
Available @ https://planetarynames.wr.usgs.gov/Feature/2164

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Henry.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > Mars. Last updated Nov. 17, 2010.
Available @ https://planetarynames.wr.usgs.gov/Feature/2452

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Maggini.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > Mars. Last updated Nov. 17, 2010.
Available @ https://planetarynames.wr.usgs.gov/Feature/3580

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

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Pasteur.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > Mars. Last updated Nov. 17, 2010.
Available @ https://planetarynames.wr.usgs.gov/Feature/4605

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

Lavoie, Sue, site mgr. “PIA00172: MC-12 Arabia Region.” NASA Jet Propulsion Laboratory Photojournal > Catalog. Image addition date: 1998-06-05.
Available @ https://photojournal.jpl.nasa.gov/catalog/pia00172

Marriner, Derdriu. “Gill Crater Honors British Astronomer Sir David Gill.” Earth and Space News. Wednesday, June 5, 2013.
Available @ https://earth-and-space-news.blogspot.com/2013/06/gill-crater-honors-british-astronomer.html

Marriner, Derdriu. “Gill Crater Parents Eight Satellites in Near Side’s South Polar Region.” Earth and Space News. Wednesday, June 12, 2013.
Available @ https://earth-and-space-news.blogspot.com/2013/06/gill-crater-parents-eight-satellites-in.html

Storm Induced Tree Failures From Heavy Tree Weights and Weather Loads

Summary: Geoff Kempter of Asplundh Tree Expert Company links storm induced tree failures to tree weights and weather loads in cyclones, ice storms and thunderstorms.

Storms affect trees, which concern arborists; some areas are more prone to thunderstorms than others; Annual Average Severe Thunderstorm Watches per Year (20-Year Average, 1993-2012): NOAA (National Oceanic and Atmospheric Administration) National Weather Service Storm Prediction Center (SPC), Public Domain, via NOAA SPC

Storm induced tree failures acknowledge tree weights and weather loads, according to Storm Response, Part 1: Types of Storms and Their Effects on Trees in the June 2013 issue of Arborist News.

Defectiveness, failure or strength becomes the top responses of trees to icy, rainy, snowy or windy storms, according to Geoff Kempter of Asplundh Tree Expert Company. Trees carry the load of animals, equipment, people, structures and weather-related residue and of their own weight in branches, flowers, fruits, leaves, nuts, trunks and twigs. Gravity and sunlight do what the energy source and the physical force respectively do best by drawing above-ground tree loads downward and above-ground tree parts upward.

Roots enable trees to endure excess loads, exterior forces, extra stress and extreme weather until below-ground food webs experience serious damage, soil disturbances and structural defects.

Storms alone or combined with structural "defects, such as leans, decay, girdling roots, or poor branch attachments," furnish the breaking stress behind storm induced tree failures.

Clayey soils get saturated and waterlogged by prolonged downpours and floods and generate insufficient "friction between roots and soil" to sustain the "holding capacity of roots." Wind intensities sustained at 64 to 82 knots (74 to 95 miles, 119 to 153 kilometers per hour) hinder root-anchoring and trunk-stabilizing capacities of some trees. Wind intensities from 83 to 112 knots (96 to 129 miles, 154 to 208 kilometers per hour) inflict sufficient damage to snap and topple many trees.

Wind intensities of 113 to 136 knots (130 to 156 miles, 209 to 251 kilometers per hour) and up jar, snap and uproot most area trees.

Tree strength keeps up with expected, normal, prevailing, typical, usual occurrences of ice, rain, snow and wind in the absence of stressed soils and structural defects.

"[H]eavy downpours on dense foliage," stubborn ice on branches and twigs, and wet snow on leafed-out trees let even strong trees become storm induced tree failures. Storms, whether atypical or prevalent in an area, may "come in many forms, and the damage to trees varies depending on storm type, location, and intensity." Governments notify an area's population that "conditions are favorable for storms" through watches and that storms are "imminent or occurring" through warnings to take "immediate" action.

The Rocky Mountain chinook, the Nor'easter, and the Santa Ana of California and Mexico offer examples of "high-wind phenomena" monitored seasonally in specific North American locales.

Cyclones and hurricanes, ice storms and thunderstorms respectively provide regional, seasonal high-wind examples of Atlantic and Pacific coastal, snow-prone, and central and Gulf coastal North America.

Circulating, low atmospheric pressure, rainy, widespread, windy systems over summer transitioning into autumn's warm waters qualify as counterclockwise-rotating northerly hurricanes and typhoons and clockwise-rotating southerly cyclones. Central and Gulf coastal North America's rising unstable thunderstorms reach hourly 100-plus-mile (161-plus-kilometer) speeds over 240-plus-mile (386-plus-kilometer) distances as derechos and 200-plus-mile (322-plus-kilometer) speeds in tornados. Ice storms shower warm-aired rain down to autumn's and spring's below-freezing landscapes as wet snow, "lower than a 10:1 snow-to-water" equivalent, that snap leafed-out weighted-down trees.

Storm induced tree failures turn private and public spaces into obstacle courses whose dangers trend less ominously when tree specialists treat site stresses and structural defects.

Arborists in North America contend with damage inflicted upon trees by Atlantic and Pacific hurricanes; worldwide hurricane tracks, 1950-2005: NOAA, Public Domain, via NOAA SOS (Science on a Sphere)

Acknowledgment

My special thanks to:
talented artists and photographers/concerned organizations who make their fine images available on the internet;
University of Illinois at Urbana-Champaign for superior on-campus and on-line resources.

Image credits:

Storms affect trees, which concern arborists; some areas are more prone to thunderstorms than others; Annual Average Severe Thunderstorm Watches per Year (20-Year Average, 1993-2012): NOAA (National Oceanic and Atmospheric Administration) National Weather Service Storm Prediction Center (SPC), Public Domain, via NOAA SPC @ http://www.spc.noaa.gov/wcm/

Arborists in North America contend with damage inflicted upon trees by Atlantic and Pacific hurricanes; worldwide hurricane tracks, 1950-2005: NOAA, Public Domain, via NOAA SOS (Science on a Sphere) @ http://sos.noaa.gov/Datasets/dataset.php?id=539

For further information:

Gilman, Ed. 2011. An Illustrated Guide to Pruning. Third Edition. Boston MA: Cengage.

Hayes, Ed. 2001. Evaluating Tree Defects. Revised, Special Edition. Rochester MN: Safe Trees.

Kempter, Geoff. June 2013. "Storm Response, Part 1: Types of Storms and Their Effects on Trees." Arborist News 22(3): 12-19.
Available @ http://viewer.epaperflip.com/Viewer.aspx?docid=ddc3c70b-f119-40bf-a3da-a29d00e3748c#?page=12

Marriner, Derdriu. 13 April 2013. “Urban Tree Root Management Concerns: Defects, Digs, Dirt, Disturbance.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2013/04/urban-tree-root-management-concerns.html

Marriner, Derdriu. 16 February 2013. “Tree Friendly Beneficial Soil Microbes: Inoculations and Occurrences.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2013/02/tree-friendly-beneficial-soil-microbes.html

Marriner, Derdriu. 15 December 2012. “Healthy Urban Tree Root Crown Balances: Soil Properties, Soil Volumes.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2012/12/healthy-urban-tree-root-crown-balances.html

Marriner, Derdriu. 13 October 2012. “Tree Adaptive Growth: Tree Risk Assessment of Tree Failure, Tree Strength.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2012/10/tree-adaptive-growth-tree-risk.html

Marriner, Derdriu. 11 August 2012. “Tree Risk Assessment Mitigation Reports: Tree Removal, Tree Retention?” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2012/08/tree-risk-assessment-mitigation-reports.html

Marriner, Derdriu. 16 June 2012. “Internally Stressed, Response Growing, Wind Loaded Tree Strength.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2012/06/internally-stressed-response-growing.html

Marriner, Derdriu. 14 April 2012. “Three Tree Risk Assessment Levels: Limited Visual, Basic and Advanced.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2012/04/three-tree-risk-assessment-levels.html

Marriner, Derdriu. 19 February 2012. “Qualitative Tree Risk Assessment: Risk Ratings for Targets and Trees.” Earth and Space News. Sunday.
Available @ https://earth-and-space-news.blogspot.com/2012/02/qualitative-tree-risk-assessment-risk.html

Marriner, Derdriu. 18 February 2012. “Qualitative Tree Risk Assessment: Falling Trees Impacting Targets.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2012/02/qualitative-tree-risk-assessment.html

Marriner, Derdriu. 10 December 2011. “Tree Risk Assessment: Tree Failures From Defects and From Wind Loads.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2011/12/tree-risk-assessment-tree-failures-from.html

Marriner, Derdriu. 15 October 2011. “Five Tree Felling Plan Steps for Successful Removals and Worker Safety.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2011/10/five-tree-felling-plan-steps-for.html

Marriner, Derdriu. 13 August 2011. “Natives and Non-Natives as Successfully Urbanized Plant Species.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2011/08/natives-and-non-natives-as-successfully.html

Marriner, Derdriu. 11 June 2011. “Tree Ring Patterns for Ecosystem Ages, Dates, Health and Stress.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2011/06/tree-ring-patterns-for-ecosystem-ages.html

Marriner, Derdriu. 9 April 2011. “Benignly Ugly Tree Disorders: Oak Galls, Powdery Mildew, Sooty Mold, Tar Spot.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2011/04/benignly-ugly-tree-disorders-oak-galls.html

Marriner, Derdriu. 12 February 2011. “Tree Load Can Turn Tree Health Into Tree Failure or Tree Fatigue.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2011/02/tree-load-can-turn-tree-health-into.html

Marriner, Derdriu. 11 December 2010. “Tree Electrical Safety Knowledge, Precautions, Risks and Standards.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2010/12/tree-electrical-safety-knowledge.html

Louis Legrand Artworks: Forgotten Precursors to Toulouse-Lautrec

Summary: Collections, galleries and museums cull Louis Legrand artworks even though posterity credits artists such as Toulouse-Lautrec with Legrand's trendsetting.

Danseuse (planche en couleur d'apres la peinture) by French artist Louis Legrand (Sep. 28, 1863-June 12, 1951); Camille Mauclair's Louis Legrand (1910), opposite page 222: Not in copyright, via Internet Archive

Louis Legrand artworks appeal to an assorted, albeit abbreviated, audience of art appreciators and art collectors even though their thematic approaches to Parisian night life anticipate other, more famous French 19th-century artists.

Louis Auguste Mathieu Legrand (Sep. 28, 1863-June 12, 1951) became a bank clerk and then an artist of book and magazine illustrations, engravings, etchings and paintings. The compositions Naturalism, against Émile Édouard Charles Antoine Zola (April 2, 1840-Sep. 28, 1902), and Prostitution caused Legrand's obscenity conviction and, for not paying fines, incarceration. Dancers respectively dominated Gil Blas illustré ("illustrated magazine"), Cours de danse fin-de-siècle ("End-of-the-century Dance Classes") and Petites du ballet ("Little Ballerinas") in 1891, 1892 and 1893.

Louis Legrand artworks respectively embellished Quinze Histoires d'Edgar Poe ("15 Stories") and Cinq contes parisiens de Guy de Maupassant ("Five Parisian Tales") in 1897 and 1905.

The aquatint and drypoint Fin ("End") and the aquatint Joie Maternelle ("Maternal Joy") from 1900 fit into Yale University's Henry Cushing/John Hay Whitney Medical Library collection.

The aquatint Chansons en Si and the black crayon and pastel watercolor Songs in the Key of B grace The Cleveland Museum of Art in Ohio. The Fine Arts Museums of San Francisco have the untitled graphite on paper drawing of a man holding a rope ladder to help a female climber. The California museums-based collections include Titi, ma petite chatte bien aimée morte à 11 ans le 2 février 1912, drypoint of Legrand's beloved dead 11-year-old kitty-cat.

The color-etched aquatint Les Cyclistes ("The Bicyclists"), lithograph Sur le Banc ("On the Beach") and prints The Gleaners and Ophele join California's 36-plus Louis Legrand artworks.

Manhattan's Museum of Modern Art keeps the photolithographic illustration for Excentricités de la Danse ("Eccentricities of the Dance") from Gil Blas Illustré ("Gil Blas [Magazine] Illustrated").

Galleries, such as Armstrong Fine Art in Chicago, Illinois, and museums in Europe and North America list Louis Legrand artworks among their acquisitions of "remarkable artists." Richard Reed Armstrong's (June 13, 1944- June 8, 2013) Armstrong Fine Art, gallery in Chicago, Illinois, of dealer Bernard Derroitte since 2006, lists Louis Legrand artworks. The couple hundred to couple thousand dollars for Louis Legrand artworks never match sales of Henri Marie Raymond de Toulouse-Lautrec-Monfa (Nov. 24, 1864-Sep. 9, 1901) artworks. And yet Legrand first nestled bar-hopping, café-going, cancan-kicking, music hall-dancing women of Paris's 18th arrondissement (district) into Belle Époque ("Beautiful Era," 1890-1914) engravings, etchings and paintings.

École des Beaux-Arts de Dijon ("School of Fine Arts of Dijon") curricula and Félicien Rops's (July 7, 1833-Aug. 23, 1898) engraving courses occasioned Louis Legrand artworks.

Anatole Devosge (Jan. 13, 1770-Dec. 8, 1850) prize-winning in 1883 and Siegfried Bing (Feb. 26, 1838-Sep. 6, 1905) gallery exhibitions in 1896 prompted Legrand's prescient productivity.

Louis Legrand artworks queued up in Paris's 1900 Exposition Universelle ("Universal Exposition") as silver medal winners, and 1902 Salon des artistes français ("Salon of French Artists"). They respectively rated Paris's Georges Petit (March 11, 1856-May 12, 1920) Gallery and Paul Durand-Ruel (Oct. 31, 1831-Feb. 5, 1922) Gallery exhibitions in 1904 and 1911. Dancers and rural Breton families respectively surfaced again in Petite Classe ("Small Class") in 1908 and anew in Au cap de la chèvre ("On Goat Promontory").

What thrust the trendsetting National Order of the Legion of Honour knight (chevalier de l'Ordre national de la Légion d'honneur) of 1906 into posthumous collective oblivion?

Louis Legrand's etched self-portrait, with inscription "à Eugène Rodrigues, mon meilleur ami," on cover of Louis Legrand Peintre et Graveur by Erastatèn Ramiro (pseudonym of Eugène Rodrigues): Not in copyright, via Internet Archive

Acknowledgment

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

Image credits:

Danseuse (planche en couleur d'apres la peinture) by French artist Louis Legrand (Sep. 28, 1863-June 12, 1951); Camille Mauclair's Louis Legrand (1910), opposite page 222: Not in copyright, via Internet Archive @ https://archive.org/stream/louislegrandpein00maucuoft#page/n284/mode/1up

Louis Legrand's etched self-portrait, with inscription "à Eugène Rodrigues, mon meilleur ami," on cover of Louis Legrand Peintre et Graveur by Erastatèn Ramiro (pseudonym of Eugène Rodrigues): Not in copyright, via Internet Archive @ https://archive.org/details/gri_33125012871931/page/n6/mode/1up

For further information:

Arwas, Victor. 2006. Louis Legrand: Catalogue Raisonné. London, England: Papadakis.

"Chansons en Si: Songs in the Key of B, c. 1910." The Cleveland Museum of Art > Search the Collection > Louis Legrand.
Available @ http://www.clevelandart.org/art/1992.342

"Les Cyclistes." Fine Arts Museums of San Francisco > Search the Collections > Louis Legrand.
Available @ https://art.famsf.org/louis-auguste-mathieu-legrand/les-cyclistes-19633030771

"The Gleaners." Fine Arts Museums of San Francisco > Search the Collections > Louis Legrand.
Available @ https://art.famsf.org/louis-auguste-mathieu-legrand/gleaners-19633031740

Kahn, Gustave. 1908. "Louis Legrand et Son Oeurvre." L'Art et Le Beau, no. 5. Paris, France: La Librarie Artistique et Littéraire.
Available via Gallica @ https://gallica.bnf.fr/ark:/12148/bpt6k97602337/f11.image.texteImage

"Louis Legrand." Museum of Modern Art > Art and Artists.
Available @ https://www.moma.org/collection/works/13937?artist_id=7675&locale=en&page=1&sov_referrer=artist

Mauclair, Camille. 1910. Louis Legrand, Peintre et Graveur. Paris, France: H. Floury; G. Pellet.
Available via Internet Archive @ https://archive.org/details/louislegrandpein00maucuoft

Marriner, Derdriu. 24 May 2013. "Henri de Toulouse-Lautrec Painting Rousse in Elementary Episode The Woman." Earth and Space News. Friday.
Available @ https://earth-and-space-news.blogspot.com/2013/05/henri-de-toulouse-lautrec-painting.html

"Ophele." Fine Arts Museums of San Francisco > Search the Collections > Louis Legrand.
Available @ https://art.famsf.org/louis-auguste-mathieu-legrand/ophele-19633031743

Ramiro, E. (Erastène). 1896. Louis Legrand Peintre-Graveur. Catalogue de son œuvre gravé et lithographié. Paris, France: H. Floury.
Available via Internet Archive @ https://archive.org/stream/gri_33125012871931#page/n9/mode/2up

"Recent Acquisitions." Yale University > Yale University Library > Medical Library.
Available @ https://library.medicine.yale.edu/historical/explore/acq

"Songs in the Key of B, c. 1910." The Cleveland Museum of Art > Search the Collection > Louis Legrand.
Available @ http://www.clevelandart.org/art/1980.117

"Sur le on banc." Fine Arts Museums of San Francisco > Search the Collections > Louis Legrand.
Available @ https://art.famsf.org/louis-auguste-mathieu-legrand/sur-le-banc-19633031748

"Titi ma petite chatte bien aimee a Pierre Loti Morte a Mans le 2 Fevrier, 1912." Fine Arts Museums of San Francisco > Search the Collections > Louis Legrand.
Available @ https://art.famsf.org/louis-auguste-mathieu-legrand/titi-ma-petite-chatte-bien-aimee-pierre-loti-morte-mans-le-2-fevrier

"Untitled." Fine Arts Museums of San Francisco > Search the Collections > Louis Legrand.
Available @ https://art.famsf.org/louis-auguste-mathieu-legrand/untitled-199493

Gill Crater Parents Eight Satellites in Near Side’s South Polar Region

Summary: Gill Crater parents eight satellites as a high-latitude crater system occupying the near side’s south polar region.

Details of Lunar Astronautical Charts (LAC) 128 (left) and 129 (right) show Gill Crater system of primary crater Gill (LAC 129 lower center) and seven of the Gill Crater system’s eight satellites; LAC 128 Gill B, C, F, G; LAC 129 Gill A, B, C, D, H; courtesy NASA (National Aeronautics and Space Administration) / GSFC (Goddard Space Flight Center) / ASU (Arizona State University): Public Domain, via USGS Astrogeology Science Center / Gazetteer of Planetary Nomenclature

Gill Crater parents eight satellites in the near side’s south polar region as a high-latitude crater system lying to the southwest of Mare Australe (Southern Sea), near the near side’s southeastern limb.

Gill Crater is centered at minus 63.77 degrees south latitude, 75.95 degrees east longitude, according to the International Astronomical Union’s (IAU) Gazetteer of Planetary Nomenclature. The southern hemisphere crater’s northernmost and southernmost latitudes extend to minus 62.71 degrees south and minus 64.82 degrees south, respectively. The eastern hemisphere crater’s easternmost and westernmost longitudes reach 78.33 degrees east and 73.56 degrees east, respectively. Gill Crater’s diameter spans 63.9 kilometers.

Gill Crater parents eight satellites. Seven of the Gill Crater system’s eight satellites occur on their parent’s western side.

One satellite, Gill D, associates with its parent’s eastern side. Gill D’s placement qualifies it as the Gill Crater system’s most easterly satellite.

Gill D is centered at minus 63.49 degrees south, 79.97 degrees east longitude. Satellite D trims its northernmost and southernmost latitudes to minus 63.23 degrees south and minus 63.75 degrees south, respectively. It reduces its easternmost and westernmost longitudes to 80.56 degrees east and 79.37 degrees east, respectively. Gill D has a diameter of 16.02 kilometers.

Gill A occurs as a slight intrusion on its parent’s northwestern rim. Gill A is centered at minus 63.43 degrees south latitude, 73.25 degrees east longitude. Satellite A limits its northernmost and southernmost longitudes to minus 63.2 degrees south and minus 63.65 degrees south, respectively. It narrows its easternmost and westernmost longitudes to 73.73 degrees east and 72.77 degrees east, respectively. Gill A has a diameter of 13.55 kilometers.

Gill B lies to the northwest of Gill A. Gill B’s placement qualifies it as the Gill Crater system’s most northerly satellite.

Gill B is centered at minus 61.82 degrees south latitude, 70.46 degrees east longitude. Satellite B confines its northernmost and southernmost latitudes to minus 61.32 degrees south and minus 62.32 degrees south, respectively. It minimizes its easternmost and westernmost longitudes to 71.51 degrees east and 69.4 degrees east, respectively. Gill B’s diameter measures 30.12 kilometers.

Gill C neighbors to the southwest of Gill B. Gill C is centered at minus 62.42 degrees south latitude, 67.83 degrees east longitude. Satellite C finds northernmost and southernmost latitudes at minus 61.89 degrees south and minus 62.96 degrees south, respectively. It marks its easternmost and westernmost longitudes at 69 degrees east and 66.67 degrees east, respectively. Gill C’s diameter measures 32.6 kilometers.

Gill E lies to the west of Gill A. It lies to the south of Gill B and to the southeast of Gill C.

Gill E is centered at minus 63.33 degrees south latitude, 70.48 degrees east longitude. Satellite E obtains northernmost and southernmost latitudes at minus 63.1 degrees south and minus 63.56 degrees south, respectively. Its easternmost and westernmost longitudes occur at 71 degrees east and 69.97 degrees east, respectively. Gill E has a diameter of 14 kilometers.

Gill F lies to the southwest of Gill C. Gill F’s placement qualifies it as the Gill Crater system’s most southerly and most westerly satellite.

Gill F is centered at minus 63.95 degrees south latitude, 65.65 degrees east longitude. Satellite F establishes its northernmost and southernmost latitudes at minus 63.54 degrees south and minus 64.35 degrees south, respectively. It marks its easternmost and westernmost longitudes at 66.57 degrees east and 64.73 degrees east, respectively. Gill F’s diameter measure 24.55 kilometers.

Gill G resides to the east-northeast of Gill F. Gill G neighbors near Gill C’s southern rim.

Gill G is centered at minus 63.62 degrees south latitude, 68.79 degrees east longitude. Satellite G restricts its northernmost and southernmost latitudes to minus 63.04 degrees south and minus 64.2 degrees south, respectively. Its easternmost and westernmost longitudes are limited to 70.1 degrees east and 67.48 degrees east, respectively.

Gill G’s diameter spans 35.3 kilometers. Gill G’s size qualifies it as the Gill Crater system’s largest satellite.

Gill H is positioned to the east of Gill G. It lies to the southwest of Gill A and to the south-southeast of Gill E.

Gill H is centered at minus 64.08 degrees south latitude, 70.98 degrees east longitude. Satellite H records northernmost and southernmost latitudes of minus 63.94 degrees south and minus 64.22 degrees south, respectively. It registers easternmost and westernmost longitudes of 71.3 degrees east and 70.65 degrees east, respectively.

Gill H has a diameter of 8.59 kilometers. Its small diameter qualifies it as the Gill Crater system’s smallest satellite.

The takeaways for Gill Crater’s parentage of eight satellites in the near side’s south polar region are that seven of the Gill Crater system’s eight satellites associate with their parent’s western side; that Gill D occurs as the only Gill Crater system satellite located to the east of its parent; and that Gill G and Gill H rank as the Gill Crater system’s largest and smallest satellites, respectively.

Details of Lunar Astronautical Chart (LAC) 139 shows Gill Crater system’s primary crater Gill (upper right) and (upper center) three (F, G, H) of the Gill Crater system’s eight satellites; courtesy NASA (National Aeronautics and Space Administration) / GSFC (Goddard Space Flight Center) / ASU (Arizona State University): Public Domain, via USGS Astrogeology Science Center / Gazetteer of Planetary Nomenclature

Acknowledgment

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

Image credits:

Details of Lunar Astronautical Charts (LAC) 128 (left) and 129 (right) show Gill Crater system of primary crater Gill (LAC 129 lower center) and seven of the Gill Crater system’s eight satellites; LAC 128 Gill: B, C, F, G; LAC 129: Gill A, B, C, D, H; courtesy NASA (National Aeronautics and Space Administration) / GSFC (Goddard Space Flight Center) / ASU (Arizona State University): Public Domain, via USGS Astrogeology Science Center / Gazetteer of Planetary Nomenclature @ https://planetarynames.wr.usgs.gov/images/Lunar/lac_128_wac.pdf and https://planetarynames.wr.usgs.gov/images/Lunar/lac_129_wac.pdf

Details of Lunar Astronautical Chart (LAC) 139 shows Gill Crater system’s primary crater Gill (upper right) and (upper center) three (F, G, H) of the Gill Crater system’s eight satellites; courtesy NASA (National Aeronautics and Space Administration) / GSFC (Goddard Space Flight Center) / ASU (Arizona State University): Public Domain, via USGS Astrogeology Science Center / Gazetteer of Planetary Nomenclature @ https://planetarynames.wr.usgs.gov/images/Lunar/lac_139_wac.pdf

For further information:

Consolmagno, Guy; and Dan M. Davis. Turn Left at Orion. Fourth edition. Cambridge UK; New York NY: Cambridge University Press, 2011.

Grego, Peter. The Moon and How to Observe It. Astronomers’ Observing Guides. London UK: Springer-Verlag, 2005.

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Gill.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > The Moon. Last updated Oct. 18, 2010.
Available @ https://planetarynames.wr.usgs.gov/Feature/2163

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Gill A.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > The Moon. Last updated Oct. 18, 2010.
Available @ https://planetarynames.wr.usgs.gov/Feature/9484

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Gill B.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > The Moon. Last updated Oct. 18, 2010.

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Gill C.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > The Moon. Last updated Oct. 18, 2010.
Available @ https://planetarynames.wr.usgs.gov/Feature/9486

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Gill D.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > The Moon. Last updated Oct. 18, 2010.
Available @ https://planetarynames.wr.usgs.gov/Feature/9487

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Gill E.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > The Moon. Last updated Oct. 18, 2010.
Available @ https://planetarynames.wr.usgs.gov/Feature/9488

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Gill F.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > The Moon. Last updated Oct. 18, 2010.
Available @ https://planetarynames.wr.usgs.gov/Feature/9489

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Gill G.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > The Moon. Last updated Oct. 18, 2010.
Available @ https://planetarynames.wr.usgs.gov/Feature/9490

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Gill H.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > The Moon. Last updated Oct. 18, 2010.
Available @ https://planetarynames.wr.usgs.gov/Feature/9491

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Mare Australe.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > The Moon. Last updated Oct. 18, 2010.
Available @ https://planetarynames.wr.usgs.gov/Feature/3665

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

Levy, David H. Skywatching. Revised and updated. San Francisco CA: Fog City Press, 1994.

Marriner, Derdriu. “Gill Crater Honors British Astronomer Sir David Gill.” Earth and Space News. Wednesday, June 5, 2013.
Available @ https://earth-and-space-news.blogspot.com/2013/06/gill-crater-honors-british-astronomer.html

The Moon Wiki. “Gill.” The Moon > Lunar Features Alphabetically > G Nomenclature.
Available @ https://the-moon.us/wiki/Gill

The Moon Wiki. “IAU Directions.” The Moon.
Available @ https://the-moon.us/wiki/IAU_directions

Moore, Patrick, Sir. Philip’s Atlas of the Universe. Revised edition. London UK: Philip’s, 2005.