Earth and Space News: February 2014

Wednesday, February 26, 2014

Kuiper Quadrangle Is Sixth of 15 Quadrangles of the Mercurian Surface

Summary: Kuiper Quadrangle is the sixth of 15 quadrangles of the Mercurian surface and covers equatorial and low latitudes longitudinally from 0 to 72 degrees..

Kuiper Quadrangle is the sixth of 15 quadrangles of the Mercurian surface and references the Swift Planet's equatorial and low latitudes of 22 degrees south to 22 degrees north latitude, from 0 to 72 degrees west longitude.

As the sixth of Mercury's 15 quadrangles, Kuiper Quadrangle has the letter-number designation of H-6 or H06. H denotes Hermes, Greek mythology's equivalent of Roman mythology's Mercurius.

Kuiper Quadrangle's provisional name, Tricrena, derives from a northern equatorial albedo, or reflective, feature on Mercury's surface. Tricrena (Ancient Greek Τρίκρηνα, "Three Springs") references montane springs sacred to Hermes as the place in which nymphs washed him after his birth. The Tricrena Mountains were located at Pheneus, an ancient town in northeastern Arcadia, central Peloponnese, southern Greece.

Prominent local features conventionally inspire the names of Mercury's quadrangles. Kuiper Quadrangle's namesake is Kuiper Crater. The International Astronomical Union (IAU) approved the crater's name in 1976 as an exception to the convention of theming Mercury's craters around historically significant artists, authors, musicians and painters. Kuiper Crater honors Dutch American astronomer and planetary scientist Gerard Peter Kuiper (born Gerrit Pieter Kuiper; Dec. 7, 1905-Dec. 23, 1973). The NASA-owned Jet Propulsion Laboratory's (JPL) online Photojournal post of Jan. 19, 2000, "Mercury: Photomosaic of the Kuiper Quadrangle H-6," noted Dr. Kuiper's membership on the Mariner 10 Venus/Mercury imaging team and that his death happened ". . . several months before the spacecraft's arrival at Mercury." The Mariner 10 robotic space probe's first flyby of Mercury took place March 29, 1974.

Kuiper Crater is located in central southern Kuiper Quadrangle. In their Geologic Map of the Kuiper Quadrangle of Mercury, published in 1981, geologists Rene A. De Hon, D.H. Scott and James Ross Underwood Jr. recognized Kuiper Crater for "the highest albedo recorded on the planet" and noted its "central peak cluster."

Kuiper Crater is centered at minus 11.34 degrees south latitude, 31.32 degrees west longitude, according to the IAU's U.S. Geological Survey Astrogeology Science Center-maintained Gazetteer of Planetary Nomenclature. The southern hemisphere crater registers northernmost and southernmost latitudes of minus 10.61 degrees south and minus 12.06 degrees south, respectively. The young crater records easternmost and westernmost longitudes of 30.58 degrees west and 32.06 degrees west, respectively. Kuiper Crater's diameter measures 62 kilometers.

Southern Kuiper Crater overlies the northwestern rim of Murasaki Crater. The IAU approved the crater's name in 1976 in honor of Japanese Heian period novelist, poet and Imperial Court lady-in-waiting Murasaki Shikibu (ca. 1073/1078-ca. 1014/1026).

Murasaki Crater is centered at minus 12.54 degrees south latitude, 30.4 degrees west longitude. It obtains northernmost and southernmost latitudes at minus 10.99 degrees south and minus 14.08 degrees south, respectively. It marks its easternmost and westernmost longitudes at 28.81 degrees west and 32 degrees west, respectively. Murasaki Crater's diameter spans 132 kilometers.

Two of Mercury's three named crater chains, termed catenae (Latin: "chains"), reside in Kuiper Quadrangle. Goldstone Catena's northeast-southwest trend near Murasaki's southwestern rim places the chain of craters to the southwest of Kuiper Crater. Northwest-to-southeast trending Haystack Catena lies across the equator, in Mercury's northern hemisphere, to the northwest of Kuiper Crater.

Goldstone Catena's name was approved Mar 26, 2013, in accordance with the convention of theming catenae around radio telescope facilities. Goldstone Deep Space Communications Complex (GDSCC), known as the Goldstone Observatory, is located in the Mohave Desert near Barstow in southeastern California's San Bernardino County. The satellite ground station eponymizes the nearby gold-mining ghost town of Goldstone.

Goldstone Catena is centered at minus 15.62 degrees south latitude, 32.02 degrees west longitude. The southern hemisphere crater chain places its northernmost and southernmost latitudes at minus 14.71 degrees south and minus 16.75 degrees south, respectively. It establishes its easternmost and westernmost longitudes at 31.5 degrees west and 32.73 degrees west, respectively. Goldstone Catena has a diameter of 102 kilometers.

Haystack Catena is centered at 4.42 degrees north latitude, 46.48 degrees west longitude. The northern hemisphere catena's northernmost and southernmost latitudes occur at 6.52 north degrees and 1.91 degrees north, respectively. It posts easternmost and westernmost longitudes of 45.3 degrees west and 47.57 degrees west, respectively. Haystack Catena's diameter of 274 kilometers qualifies it as the larger of Kuiper Quadrangle's two chains of craters.

Kuiper Quadrangle reaches across Mercury's crater to claim Victoria Quadrangle (H-2) as its only northern neighbor. Equator-straddling Derain Quadrangle (H-10) shares Kuiper Quadrangle's eastern border. Discovery Quadrangle (H-11) is contiguous with Kuiper Quadrangle's southern border. Beethoven Quadrangle (H-7) occurs as Kuiper Quadrangle's western neighbor.

The takeaways for Kuiper Quadrangle as the sixth of 15 quadrangles of the Mercurian surface are that the quadrangle's namesake feature, Kuiper Crater, honors Dutch American astronomer and planetary scientist Gerard Kuiper, who was a member of the Mariner 10 Venus/Mercury imaging team; that Kuiper Crater claims Mercury's highest albedo record; that two of Mercury's three crater chains (Latin: catenae) are found in Kuiper Quadrangle; that the equator-straddling quadrangle claims the northern hemisphere's Victoria Quadrangle and the southern hemisphere's Discovery Quadrangle as northern and southern neighbors, respectively; and that equator-straddling Derain and Beethoven quadrangles neighbor along Kuiper Quadrangle's eastern and western borders, respectively.

Detail of Map of the H-6 (Kuiper) Quadrangle of Mercury shows the quadrangle's namesake, Kuiper Crater (lower center), overlying Murasaki Crater, and two of Mercury's three catenae, Goldstone (lower center), southwest of Kuiper Crater, and Haystack (upper left), northwest of Kuiper Crater; credit NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington/USGS: courtesy IAU/USGS Astrogeology Science Center's 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:

Map of Kuiper Quadrangle shows area of northern midlatitude illuminated during the Mariner 10 robotic space probe's three Mercury flybys (March 29, 1974; Sept. 21, 1974; march 16, 1975), with easternmost 10 degrees beyond the evening terminator; Geologic Map of the Kuiper Quadrangle of Mercury by (1981) by R.A. De Hon, D.H. Scott and J.R. Underwood Jr, prepared on behalf of the Planetary Geology Program, Planetary Division, Office of Space Science, National Aeronautics and Space Administration: via USGS Publications Warehouse @ https://pubs.usgs.gov/imap/1233/plate-1.pdf; courtesy of U.S. Geological Services, via USGS Astrogeology Science Center's data portal, Astropedia, @ https://astrogeology.usgs.gov/search/map/Mercury/Geology/Mercury-Geologic-Map-of-the-Kuiper-Quadrangle

Antoniadi, E.M. (Eugène Michel). La Planète Mercure et la Rotation des Satellites. Paris, France: Gauthier-Villars, 1934.

Cruikshank, Dale P. Biographical Memoir of Gerard Peter Kuiper 1905-1975. National Academy of Sciences. Biographical Memoir. Washington DC: National Academy of Sciences, 1993.
Available @ http://www.nasonline.org/publications/biographical-memoirs/memoir-pdfs/kuiper-gerard.pdf

Davies, Merton E.; Stephen E. Dwornik; Donald E. Gault; and Robert G. Strom. Atlas of Mercury. Special Publication SP-423. Prepared for the Office of Space Sciences. Washington DC: National Aeronautics and Space Administration Scientific and Technical Information Office, 1978.
Available @ https://history.nasa.gov/SP-423/

Davies, Merton E.; Stephen E. Dwornik; Donald E. Gault; and Robert G. Strom. "H-6 Kuiper Quadrangle." Atlas of Mercury: 58-73. Special Publication SP-423. Prepared for the Office of Space Sciences. Washington DC: National Aeronautics and Space Administration Scientific and Technical Information Office, 1978.
Available @ https://history.nasa.gov/SP-423/h6.htm

De Hon, R.A. (Rene A.); D.H. (David H.) Scott; and J.R. (James Ross) Underwood, Jr. Geologic Map of the Kuiper Quadrangle of Mercury. IMAP 1233 H-6. Atlas of Mercury 1:5,000,000 Geologic Series. Prepared for the National Aeronautics and Space Administration. Reston VA: U.S. Geological Survey, Nov. 20, 1981.
Available via USGS Astrogeology Science Center's Astropedia Web Portal @ https://astrogeology.usgs.gov/search/map/Mercury/Geology/Mercury-Geologic-Map-of-the-Kuiper-Quadrangle
Available via USGS Publications Warehouse @ https://pubs.usgs.gov/imap/1233/plate-1.pdf

Hapke, Bruce; G.E. (Edward) Danielson, Jr.; Kenneth Klaasen; and Lionel Wilson. 1975. "Photometric Observations of Mercury From Mariner 10." Journal of Geophysical Research, vol. 80, no. 17 (June 10, 1975): 2431–2443.
Available via Wiley Online Library @ https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/JB080i017p02431

International Astronomical Union. Information Bulletin, no. 108. July 2011. Paris, France: Printed on behalf of IAU Secretariat by Presse Pluriel, July 12, 2011.
Available @ https://www.iau.org/static/publications/IB108.pdf

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. “Coordinate Systems for Planets and Satellites.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Documentation > Target Coordinate Systems.
Available @ https://planetarynames.wr.usgs.gov/TargetCoordinates

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Descriptor Terms (Feature Types).” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Documentation > Descriptor Terms.
Available @ https://planetarynames.wr.usgs.gov/DescriptorTerms

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Goldstone Catena.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > Mercury. Last updated Oct. 11, 2016.
Available @ https://planetarynames.wr.usgs.gov/Feature/15107

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Haystack Catena.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > Mercury. Last updated Oct. 11, 2016.
Available @ https://planetarynames.wr.usgs.gov/Feature/15108

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Kuiper.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > Mercury. Last updated Oct. 11, 2016.
Available @ https://planetarynames.wr.usgs.gov/Feature/3140

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Murasaki.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > Mercury. Last updated Oct. 12, 2016.
Available @ https://planetarynames.wr.usgs.gov/Feature/4071

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

Jet Propulsion Laboratory. "PIA02236: Mercury: Photomosaic of the Kuiper Quadrangle H-6." NASA JPL Photojournal. Image addition date 2000-01-19.
Available @ https://photojournal.jpl.nasa.gov/catalog/PIA02236

Lunar and Planetary Institute. "Mercury Map Catalog." Lunar and Planetary Institute > Resources.
Available @ https://www.lpi.usra.edu/resources/mercury_maps/

Marriner, Derdriu. "Borealis Quadrangle Is First of 15 Quadrangles of Mercurian Surface." Earth and Space News. Wednesday, Jan. 15, 2014.
Available @ https://earth-and-space-news.blogspot.com/2014/01/borealis-quadrangle-is-first-of-15.html

Marriner, Derdriu. "Hokusai Quadrangle Is Fifth of 15 Quadrangles of Mercurian Surface." Earth and Space News. Wednesday, Feb. 19, 2014.
Available @ https://earth-and-space-news.blogspot.com/2014/02/hokusai-quadrangle-is-fifth-of-15.html

Marriner, Derdriu. "Raditladi Quadrangle Is Fourth of 15 Quadrangles of Mercurian Surface." Earth and Space News. Wednesday, Feb. 12, 2014.
Available @ https://earth-and-space-news.blogspot.com/2014/01/raditladi-quadrangle-is-fourth-of-15.html

Marriner, Derdriu. "Shakespeare Quadrangle Is Third of 15 Quadrangles of Mercurian Surface." Earth and Space News. Wednesday, Jan. 29, 2014.
Available @ https://earth-and-space-news.blogspot.com/2014/01/shakespeare-quadrangle-is-third-of-15.html

Marriner, Derdriu. "Victoria Quadrangle is Second of 15 Quadrangles of Mercurian Surface." Earth and Space News. Wednesday, Jan. 22, 2014.
Available @ https://earth-and-space-news.blogspot.com/2014/01/victoria-quadrangle-is-second-of-15.html

Morrison, David. "IAU Nomenclature for Topographic Features on Mercury." Icarus, vol. 28, issue 4 (August 1976): 605-606
Available via ScienceDirect @ https://www.sciencedirect.com/science/article/abs/pii/0019103576901342?via%3Dihub

U.S. Geological Survey. Shaded Relief Map of the Kuiper Quadrangle of Mercury (Tricrena Albedo Province). IMAP 960 H-6. Atlas of Mercury 1:5,000,000 Topographic Series. Prepared on behalf of the Planetology Programs Office, National Aeronautics and Space Administration. Reston VA: U.S. Geological Survey, 1976.
Available via USGS Astrogeology Science Center's Astropedia Web Portal @ https://astrogeology.usgs.gov/search/map/Mercury/Topography/Mercury-Shaded-Relief-Map-of-the-Kuiper-Quadrangle
Available via USGS Publications Warehouse @ https://pubs.er.usgs.gov/publication/i960

Wednesday, February 19, 2014

Hokusai Quadrangle Is Fifth of 15 Quadrangles of Mercurian Surface

Summary: Hokusai Quadrangle is the fifth of 15 quadrangles of the Mercurian surface and covers northern midlatitudes longitudinally from 270 to 360 degrees.

Brightly haloed Hokusai Crater's extensive rays dominate and extend beyond northern Mercury's Hokusai Quadrangle: approximate color representation combines three images acquired by MESSENGER Wide Angle Camera (EW0131772418F, EW0131772423G, EW0131772431I) obtained by MESSENGER Wide Angle Camera (WAC) during second flyby, Oct. 6, 2008; PILOT (Planetary Image Locator Tool), USGS Astrogeology Science Center: James Stuby (Jstudy), Public Domain, via Wikimedia Commons

Hokusai Quadrangle is the fifth of 15 quadrangles of the Mercurian surface, and its map covers the Swift Planet's low and middle latitudes of 21 to 66 degrees north latitude, from 270 to 360 degrees west longitude.

As the fifth of Mercury's 15 quadrangles, Hokusai Quadrangle has the letter-number designation of H-5 or H05. H signifies Hermes, Greek mythology's Olympian deity who equates to Roman mythology's Mercurius.

Hokusai Quadrangle's provisional name, Apollonia, designates an albedo feature on Mercury's surface. Greek French astronomer Eugène Michel Antoniadi (March 1, 1870-Feb. 10, 1944) placed Apollonia north of 60 degrees north latitude on the map of Mercury's albedo features in his guide, La Planète Mercure, published in 1934 and translated into English by English amateur astronomer Sir Patrick Moore (March 4, 1923-Dec. 9, 2012) in 1974 (figure 5, page 26).

Mercury's quadrangles conventionally receive their names from prominent features. Hokusai Quadrangle's namesake is Hokusai Crater. The International Astronomical Union (IAU) has themed Mercury's craters around historically significant artists, authors, musicians and painters, according to the IAU's U.S.G.S. (U.S. Geological Survey) Astrogeology Science Center-maintained, online Gazetteer of Planetary Nomenclature. Hokusai Crater 's name, which received IAU approval on Mar 3, 2010, honors Japanese Edo period artist, ukiyo-e painter and printmaker Katsushita Hokusai (Oct. 31, 1760-May 10, 1849).

Hokusai Crater is centered at 57.84 degrees north latitude, 343.35 degrees west longitude, according to the IAU's Gazetteer of Planetary Nomenclature. The northern middle latitude crater obtains northernmost and southernmost latitudes of 59 degrees north and 56.67 degrees north, respectively. It finds its easternmost and westernmost longitudes at 341.25 degrees west and 345.46 degrees west, respectively. Hokusai Crater's diameter measures 114 kilometers.

Hokusai Crater was discovered through ground-based radar observations conducted in 1991 at Goldstone Deep Space Communications Complex (GDSCC), known as Goldstone Observatory, located in the Mojave Desert near Barstow in southeastern California's San Bernardino County. Prior to its official name, Hokusai Crater was identified as feature B. Radar astronomer John K. Harmon and five co-authors described feature B as a very brightly haloed, yet less distinctively rayed crater in their article on non-polar region radar imaging of Mercury in the April 2007 issue of Icarus. The reseachers rated feature B as one of "three of the most prominent crater features" studied via the S-band radar telescope at the National Science Foundation's (NSF) Arecibo Observatory, also known as National Astronomy and Ionosphere Center (NAIC), located Barrio Esperanza, Arecibo, northern coastal Puerto Rico.

Prior to NASA's MESSENGER (Mercury Surface, Space Environment, Geochemistry, and Ranging) mission, Hokusai Crater was viewed only via Earth-based radar images. The MESSENGER robotic space probe's second flyby, Oct. 6, 2008, yielded the first spacecraft-obtained images of the brightly haloed crater. The NASA-owned Jet Propulsion Laboratory's (JPL) online Photojournal post of Oct. 7, 2008, "Mercury As Never Seen Before," noted that the young crater's "extensive ray system" radiated across Mercury's northern region and extended southward across the equator. Photojournal's Oct. 9, 2008, post, "Looking Back to the Source," observed: "The amazing extent of this large ray system is visible for the first time in MESSENGER’s newly acquired images."

Hokusai Crater occurs in Hokusai Quadrangle's northwestern corner. Its location places the impact crater in Borealis Planitia ("Northern Plain"). Although centered in Hokusai Quadrangle's northern neighbor, Borealis Quadrangle, Borealis Planitia intrudes into much of northern Hokusai Quadrangle.

Borealis Planitia received name approval in 1976. The northern hemisphere plain joins Caloris Planitia (Hot Plain) as the two exceptions to the IAU convention of theming Mercury's plains (Latin: planitiae) with names of Mercury, as god or planet, in various languages.

Borealis Planitia is centered at 67.3 degrees north latitude, 327.4 degrees west longitude. Its northernmost and southernmost latitudes extend to 86.9 degrees north and 29.5 degrees north, respectively. Its easternmost and westernmost longitudes reach 225.4 degrees west and 134.6 degrees west, respectively. Borealis Planitia's diameter spans 3,450 kilometers.

Hokusai Quadrangle's reach to 66 degrees north latitude establishes Borealis Quadrant (H-1) as the quadrangle's only northern neighbor. Hokusai Quadrangle's coverage of low and middle latitudes of Mercury's northern hemisphere allows for a shared eastern border with Raditladi Quadrangle (H-4) and western contiguity with Victoria Quadrangle (H-1). Eminescu Quadrangle (H-9) briefly shares Hokusai Quadrangle's southeastern border while Derain Quadrangle (H-10) claims most of Hokusai Quadrangle's southern border.

Hokusai Quadrangle numbers among the six quadrangles unimaged by Mariner 10, the first spacecraft visitor to Mercury. Mariner 10 mission's three flybys (March 29, 1974; Sept. 21, 1974; March 16, 1975). The portion of Mercury's surface covered by Hokusai, Raditladi, Eminescu, Derain, Debussy and Neruda quadrangles was not illuminated during the Mariner 10 mission's three flybys (March 29, 1974; Sept. 21, 1974; March 16, 1975). NASA's MESSENGER robotic space probe revealed the previously unimaged hemisphere via its first flyby, Jan. 14, 2008.

The takeaways for Hokusai Quadrangle as the fifth of 15 quadrangles of the Mercurian surface are that the northern low through middle latitude quadrangle's name derives from the area's brightly haloed, extensively rayed Hokusai Crater; that Hokusai Crater honors Japanese Edo period artist, ukiyo-e painter and printmaker Tasushita Hokusai; that northern neighbor Borealis Quadrangle;s vast plain, Borealis Planitia (Northern Plain), extends into northern Hokusai Quadrangle; and that, in addition to Borealis Quadrangle, Hokusai Quadrangle shares its borders with eastern neighbor Raditladi Quadrangle, southern neighbors Eminescu and Derain quadrangles and western neighbor Victoria Quadrangle.

Acknowledgment

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

Image credits:

Some rays in Hokusai Crater's (foreground) famous extensive ray stem traverse over 1,000 miles of the Mercurian surface; MESSENGER image acquired via the robotic space probe's Mercury Dual Imaging System's (MDIS) high-incidence-angle base map; credit NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington; uploaded Sep. 27, 2013: NASA Goddard Space Flight Center (NASA Goddard Photo and Video), CC BY 2.0 Generic, via Flickr @ https://www.flickr.com/photos/gsfc/9967761663/; CC BY 2.0 Generic, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:Crater_Hokusai,_Mercury,_MESSENGER.jpg

For further information:

Antoniadi, E.M. (Eugène Michel). La Planète Mercure et la Rotation des Satellites. Paris, France: Gauthier-Villars, 1934.

Denevi, Brett W., Carolyn M. Ernst; Louise M. Prockter; and Mark S. Robinson. "Chapter 6: The Geologic History of Mercury." Pages 144-175. In Sean C. Solomon; Larry R. Nittler; and Brian J. Anderson, eds., Mercury: The View After MESSENGER. Cambridge Planetary Science. Cambridge UK: Cambridge University Press, 2018.
Available via Google Books @ https://books.google.com/books?id=4o92DwAAQBAJ&pg=PA144

Harmon, John K.; Martin A. Slade; Bryan J. Butler; James W. Head; Melissa S. Rice; and Donald B. Campbell. "Mercury: Radar Images of the Equatorial and Midlatitude Zones." Icarus, vol. 187, issue 2 (April 2007): 374–405. DOI: 10.1016/j.icarus.2006.09.026
Available via ScienceDirect @ https://www.sciencedirect.com/science/article/abs/pii/S0019103506003599?via%3Dihub

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Borealis Planitia.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > Mercury. 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. “Caloris Planitia.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > Mercury. Last updated May 25, 2016.
Available @ https://planetarynames.wr.usgs.gov/Feature/979

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Hokusai.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > Mercury. Last updated Oct. 11, 2016.
Available @ https://planetarynames.wr.usgs.gov/Feature/14644

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Victoria Rupes.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > Mercury. Last updated Oct. 14, 2016.
Available @ https://planetarynames.wr.usgs.gov/Feature/6379

Jet Propulsion Laboratory. "PIA10172: MESSENGER's First Look at Mercury's Previously Unseen Side." NASA JPL Photojournal. Image addition date 2008-01-15.
Available @ https://photojournal.jpl.nasa.gov/catalog/PIA10172

Jet Propulsion Laboratory. "PIA11245: Mercury as Never Seen Before." NASA JPL Photojournal. Image addition date 2008-10-07.
Available @ https://photojournal.jpl.nasa.gov/catalog/PIA11245

Jet Propulsion Laboratory. "PIA11356: Looking Back to the Source." NASA JPL Photojournal. Image addition date 2008-10-09.
Available @ https://photojournal.jpl.nasa.gov/catalog/PIA11356

MESSENGER. "Hokusai Paints a Wave of Rays." The Johns Hopkins University Applied Physics Laboratory (JHUAPL) MESSENGER > Gallery. May 11, 2010.
Available @ https://web.archive.org/web/20131005001754/http://messenger.jhuapl.edu/gallery/sciencePhotos/image.php?gallery_id=2&image_id=381

MESSENGER. "Looking Back to the Source." The Johns Hopkins University Applied Physics Laboratory (JHUAPL) MESSENGER > Gallery. Oct. 9, 2008.
\ Available @ https://web.archive.org/web/20131006053822/http://messenger.jhuapl.edu/gallery/sciencePhotos/image.php?page=3&search_type=and&image_id=226

MESSENGER. "MESSENGER Team Releases First Global Map of Mercury." The Johns Hopkins University Applied Physics Laboratory (JHUAPL) MESSENGER > News Center. Dec. 15, 2009.
Available @ https://web.archive.org/web/20150414104341/http://messenger.jhuapl.edu/news_room/details.php?id=141

Saturday, February 15, 2014

Tree Twig Anatomy: Ecosystem Stress, Growth Rates, Winter Identification

Summary: Professor Kim D. Coder of Athens, Georgia, uses tree twig anatomy to research tree-related ecosystem stress, growth rates and winter identification.

Tree twig anatomy conveys details of ecosystem stress and growth rates and also provides plant identification in winter; autumn olive (Elaeagnus umbellata) twigs with thorns and leaves in spring: James H. Miller/USDA Forestry Service/Bugwood.org, CC BY 3.0 United States, via Forestry Images

Advanced Twig Anatomy: Starting Little to Get Big (Part I) addresses tree twig anatomy for indicating ecosystem stress and species growth rates and winter identification in the February 2014 Arborist News issue.

Kim D. Coder of North America's University of Georgia in Athens, Georgia, bases his discussion upon extensive experience with temperate deciduous angiosperms, also known as hardwoods. Focus and space call for excluding from discussion evergreen and persistent-leaved angiosperms and gymnosperms whose twigs confirm non-deciduous, species-specific ecosystem stress, growth rates and winter identifications. All twigs, whether angiosperm or gymnosperm, whether deciduous evergreen or persistent-leaved, deserve descriptions as "the current or most recent growth extension at the tips of branches."

Growing points emerge either "just behind and to the side" of, or within "protective bud scales" at, the tips of deciduous, evergreen and persistent-leaved tree twigs.

Twigs fit into tree twig anatomy as the first year's growth increments atop the second and the third year's branchlet attachments to the fourth year's branches. They generate growth, species and stress information by surviving cladoptosis, a tree "compartmentalization process" that naturally self-prunes and yearly sheds over 30,000 branches, branchlets and twigs.

Each twig section has to have only one each of bud-, flower- or leaf-generating nodal torus rings; growth-friendly internodes; leaves; petioles; and side or terminal buds. They include coppice shoots at stem base "suppressed growing points," crown-based long shoots with "normally elongated internodes" and root shoots with root base "adventitious growing points."

Crown-growing determinant short shoots with functional terminal growing points, indeterminant short shoots without and flower-, fruit-, leaf-generating, slow-growing, spine-tipped spur shoots join to narrow winter identification.

Tree twig anatomy keeps internodes species-specific in 1.9-millimeter (0.075-inch) slender, 4-millimeter (0.158-inch) moderately slender, 5-millimeter (0.197-inch) moderately stout or 5-plus-millimeter (0.197-plus-inch) robust or stout maximum diameters.

Cross-sectional shapes look angled, round or star-shaped for pith, the twig's primary-, soft-celled longitudinal center axis, and angular, fluted or ridged, oval or round for internodes. Pith manages chambered and multi-cross-walled, diaphragmed and thin cross-walled, excavated and hollow, solid or spongily perforated longitudinal views in declining, downward-hanging, downward-tending, drooping or upright twigs. It needs an encircling, medullary, non-ray cell-breached sheath surrounded by wood's "structural and vascular tissue" to protect chlorophyll-filled, first-year, live green pith cells from ecosystem stress.

Axil-derived, vascular tissue-filled spinescent thorn-like short spurs and spiniferous thorns or prickly epidermis- and periderm-anchored bristles and fruit-, leaf-, stipule stem-modified nodal thorns offer exterior armature.

Secondary growth, called girth expansion, pushes peridermal, secondary tissue generated by lateral meristems called phellogens crushingly against primary, simple-celled cortex supporting the bark's epidermal primary tissue. Girth quickens old phelloderm and phloem tissues intermingling as secondary cortex under corky periderm's even, mottled or striated smoothness, peeling papery-ness or furrowed, scaly, warty roughness.

Low-density, thin-walled peridermal lenticels distinctly, invisibly or visibly raised, sunken or surfacing atop epidermal gas exchange ports called stomates reveal rounding or horizontal- or longitudinal-elongated ovality. Trichomes, be they bristly, coarse, dense, flat-scaled, long, minute, silky, soft, sparse, star-shaped, stiff or straight, surface alongside lenticels on hairily pubescent, not hairlessly glabrous, twigs.

Tree twig anatomy always tells on species-specific, stress-induced characteristics, even on blue-gray caesious, blue-white glaucous, frosted-like pruinose, light-colored bloom, stickily glutinous or thickly viscid wax-coated epidermises.

Tree twigs serve as tree identifiers in winter; red maple (Acer rubrum) twig: Rob Routledge/Sault College/Bugwood.org, CC BY 3.0 United States, via Forestry Images

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:

autumn olive (Elaeagnus umbellata) twigs with thorns and leaves in spring: James H. Miller/USDA Forestry Service/Bugwood.org, CC BY 3.0 United States, via Forestry Images @ http://www.forestryimages.org/browse/detail.cfm?imgnum=0016044

Tree twigs serve as tree identifiers in winter; red maple (Acer rubrum) twig: Rob Routledge/Sault College/Bugwood.org, CC BY 3.0 United States, via Forestry Images @ http://www.forestryimages.org/browse/detail.cfm?imgnum=5488134

For further information:

Coder, Kim D. February 2014. "Advanced Twig Anatomy: Starting Little to Get Big (Part I)." Arborist News 23(1): 12-18.
Available @ http://viewer.epaperflip.com/Viewer.aspx?docid=957b5dba-214f-475b-b581-a2bb00e328be#?page=12

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.

Marriner, Derdriu. 14 December 2013. “Community and Tree Safety Awareness During Line- and Road-Clearances.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2013/12/community-and-tree-safety-awareness.html

Marriner, Derdriu. 13 October 2013. “Chain-Saw Gear and Tree Work Related Personal Protective Equipment.” Earth and Space News. Sunday.
Available @ https://earth-and-space-news.blogspot.com/2013/10/chain-saw-gear-and-tree-work-related.html

Marriner, Derdriu. 12 October 2013. “Storm Damaged Tree Clearances: Matched Teamwork of People to Equipment.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2013/10/storm-damaged-tree-clearances-matched.html

Marriner, Derdriu. 17 August 2013. “Storm Induced Tree Damage Assessments: Pre-Storm Planned Preparedness.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2013/08/storm-induced-tree-damage-assessments.html

Marriner, Derdriu. 15 June 2013. “Storm Induced Tree Failures From Heavy Tree Weights and Weather Loads.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2013/06/storm-induced-tree-failures-from-heavy.html

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

Wednesday, February 12, 2014

Raditladi Quadrangle Is Fourth of 15 Quadrangles of Mercurian Surface

Summary: Raditladi Quadrangle is the fourth of 15 quadrangles of the Mercurian surface and covers northern midlatitudes longitudinally from 180 to 270 degrees.

Raditladi Quadrangle residents Raditladi Crater (upper left), Cunningham, Kertész and Sander craters (upper center) and Apollodorus and Atget craters and Phantheon Fossae (upper right); name-labeled mosaic of Narrow Angle Camera (NAC) images shows 12 features imaged for first time via MESSENGER's first flyby Jan. 14, 2008, and announced April 9, 2008, via USGS Astrogeology Science Center as officially named and three craters (Basho in Michelangelo Quadrangle H-12; Mozart and Tolstoj in Tolstoj Quadrangle H-8) first seen by Mariner 10 mission; credit NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington; uploaded May 2, 2008, by Bryan Derksen, Public Domain, via Wikimedia Commons

Raditladi Quadrangle is the fourth of 15 quadrangles of the Mercurian surface and references the Swift Planet's low and middle latitudes of 21 to 66 degrees north latitude, from 180 to 270 degrees west longitude.

As the fourth of Mercury's 15 quadrangles, Raditladi Quadrangle has the letter-number designation of H-4 or H04. H denotes Hermes, Greek mythology's equivalent of Roman mythology's Mercurius.

Raditladi Quadrangle's provisional name, Liguria, reflects on Italy's northwest region and derives from the ancient, mysterious Ligures people, whose territory once included northwestern Italy, southern France and part of modern Catalonia in northeastern Spain. Greek French astronomer Greek French astronomer Eugène Michel Antoniadi (March 1, 1870-Feb. 10, 1944) centered Liguria at approximately 40 degrees north latitude on the map of Mercury's albedo features in his guide, La Planète Mercure, published in 1934 and translated into English by English amateur astronomer Sir Patrick Moore (March 4, 1923-Dec. 9, 2012) in 1974 (figure 5, page 26).

Mercury's quadrangles conventionally derive their names from prominent features. Raditladi Quadrangle's namesake is Raditladi Crater. The International Astronomical Union (IAU) has established names of historically significant artists, authors, musicians and painters as the theme for Mercury's craters, according to the IAU's U.S.G.S. (U.S. Geological Survey) Astrogeology Science Center-maintained, online Gazetteer of Planetary Nomenclature. Raditladi Crater received IAU approval on April 8, 2008, as the Mercurian namesake of Botswanan playwright and poet Leetile Disang Raditladi (1910-1971).

Raditladi Crater is centered at 27.15 degrees north latitude, 240.94 degrees west longitude, according to the IAU's Gazetteer of Planetary Nomenclature. The northern low latitude crater obtains northernmost and southernmost latitudes of 30.17 degrees north and 24.12 degrees north, respectively. Its easternmost and westernmost longitudes occur at 237.54 degrees west and 244.34 degrees west, respectively. Raditladi Crater's diameter measures 258 kilometers.

In their presentation, "The Curious Case of Raditladi Basin," at the 40th annual Lunar and Planetary Science Conference, held Monday, March 23, to Friday, March 27, 2009, Planetary scientist Louise M. Procktor and 11 co-authors described Raditladi Crater as distinguished structurally by an off-center peak-ring with a diameter of approximately 125 kilometers. Extensional (pulled-apart) troughs that occur as a partially concentric, circularly-patterned complex within the peak-ring structure qualify as a rarity on the Mercurian surface. The distinctive flat floors exhibited in some of the troughs are considered as graben (German: "ditch"), depressed blocks of planetary or satellite crust.

Raditladi Crater lies to the west of Caloris Planitia (Hot Plain). The IAU approved the name of southeastern Raditladi Quadrangle's huge plain in 1976 as one of two exceptions (Borealis Planitia, "Northern Plain") to the convention of assigning names of Mercury, as god or planet, in various languages to the Swift Planets plains (Latin: planitiae). In addition to its Raditladi occupancy, Caloris Planitia extends into Shakespeare Quadrangle to the east and Tolstoj Quadrangle to the south.

Caloris Planitia is centered at 31.65 degrees north latitude, 198.02 degrees west longitude. Its northernmost and southernmost latitudes extend to 48.6 degrees north and 15.54 degrees north, respectively. Its easternmost and westernmost longitudes reach 176.3 degrees west and 217.97 degrees west, respectively. Caloris Planitia's diameter spans 1,500 kilometers.

Raditladi Quadrangle lies to the south of northern polar region's Borealis Quadrangle (H-1). Shakespeare Quadrangle (H-3) and Hokusai Quadrangle (H-5) occur as Raditladi Quadrangle's eastern and western neighbors, respectively. Raditladi Quadrangle shares its southern borders with Tolstoj Quadrangle (H-8) and Eminescu Quadrangle (H-9).

Raditladi Quadrangle numbers among the six Mercurian quadrangles not imaged by the National Aeronautics and Space Administration's (NASA) Mariner 10 mission. The five other quadrangles not covered by Mariner 10 were Raditladi's western neighbor, Hokusai (H-5); Raditladi's southwestern neighbor, Eminescu (H-9); Hokusai's southern neighbor, Derain (H-10); Derain's southeastern neighbor, Debussy (H-14); and Eminescu's southern neighbor, Neruda (H-13). Images obtained from the robotic space probe's three flybys (March 29, 1974; Sept. 21, 1974; March 16, 1975) allowed mapping of nine of the 15 quadrangles that abstractly divide Mercury's surface. MESSENGER robotic space probe's explorations of Mercury removed the mapping gaps via one primary mission, beginning April 4, 2011, and two extensions.

The takeaways for Raditladi Quadrangle as the fourth of 15 quadrangles of the Mercurian surface are that the quadrangle's namesake is Botswanan playwright-honoring Raditladi Crater; that Raditladi Crater exhibits a rare feature, partially-concentric, circularly-patterned troughs thought to be graben, in its off center peak-ring structure; that the quadrangle was identified as Liguria Albedo Province in Greek-French astronomer E.M. Antoniadi's 1934 Mercury guidebook; and that Raditladi Quadrangle shares borders with northern neighbor Borealis Quadrangle, eastern neighbor Shakespeare Quadrangle, southern neighbors Tolstoj and Eminescu quadrangles, and western neighbor Hokusai Quadrangle.

Raditladi Qudrangle's namesake, off-center peak-ringed Raditladi Crater (upper left) was discovered in 3x3 mosaic of three images obtained by the Mercury Dual Imaging System's (MDIS) Wide Angle Camera (WAC) during MESSENGER robotic space probe's first Mercury flyby Jan. 14, 2008; mosaic presents first-ever view of area not covered by NASA's 1974-1975 Mariner 10 mission; credit NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington: Public Domain, via Wikimedia Commons

Acknowledgment

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

Image credits:

Antoniadi, E.M. (Eugène Michel). La Planète Mercure et la Rotation des Satellites. Paris, France: Gauthier-Villars, 1934.

Baker, David M.H.; James W.Head; Samuel C.Schon; Carolyn M.Ernst; Louise M.Prockter; Scott L.Murchie; Brett W.Denevi; Sean C.Solomon; Robert G.Strom. "The Transition From Complex Crater to Peak-Ring Basin on Mercury: New Observations From MESSENGER Flyby Data and Constraints on Basin Formation Models." Planetary and Space Science, vol. 59, issue 15 (December 2011): 1932-1948.
Available @ https://www.sciencedirect.com/science/article/abs/pii/S003206331100167X?via%3Dihub

Blewett, David T., Carolyn M. Ernst; Scott L. Murchie; and Faith Vilas. "Chapter 12: Mercury's Hollows." Pages 324-345. In Sean C. Solomon; Larry R. Nittler; and Brian J. Anderson, eds., Mercury: The View After MESSENGER. Cambridge Planetary Science. Cambridge UK: Cambridge University Press, 2018.
Available via Google Books @ https://books.google.com/books?id=4o92DwAAQBAJ&pg=PA324

Campbell, Paulette. "Mercury Features Receive New Names." The Johns Hopkins University Applied Physics Laboratory > News & Publications > News. April 28, 2008.
Available @ https://www.jhuapl.edu/PressRelease/080428

Dzurisin, Daniel. "Mercurian Bright Patches: Evidence for Physio-Chemical Alteration of Surface Material?" Geophysical Research Letters, vol. 4, issue 10 (October 1977) 383-386. DOI: 10.1029/GL004i010p00383
Available via Wiley Online Library @ https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/GL004i010p00383

Head, James W. Head; Scott L. Murchie; Louise M. Prockter; Sean C. Solomon; Robert G. Strom; Clark R. Chapman; Thomas R. Watters; David T. Blewett; J.J. Gillis-Davis; Caleb I. Fassett; James L. Dickson; Debra M. Hurwitz; and Lillian R. Ostracha. "Evidence for Intrusive Activity on Mercury From the First MESSENGER Flyby." Earth and Planetary Science Letters, vol. 285, issues 3-4 (Aug. 15, 2009): 251-262.
Available via ScienceDirect @ https://www.sciencedirect.com/science/article/abs/pii/S0012821X09001514?via%3Dihub

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Raditladi.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > Mercury. Last updated Oct. 12, 2016.
Available @ https://planetarynames.wr.usgs.gov/Feature/14387

Lakdawalla, Emily. "What Are Mercury's Hollows?" The Planetary Society > Explore Space > Articles. Feb. 18, 2014.
Available @ https://www.planetary.org/articles/02171332-what-are-mercurys-hollows

Marriner, Derdriu. "Mercury's Munch Crater Honors Norwegian Painter Edvard Munch." Earth and Space News. Wednesday, Jan. 8, 2014.
Available @ https://earth-and-space-news.blogspot.com/2014/01/mercurys-munch-crater-honors-norwegian.html

Marriner, Derdriu. "Mercury's Poe Crater Honors American Poet and Writer Edgar Allan Poe." Earth and Space News. Wednesday, Jan. 1, 2014.
Available @ https://earth-and-space-news.blogspot.com/2014/01/mercurys-poe-crater-honors-american.html

MESSENGER. "Double Ring Crater." Johns Hopkins University Applied Physics Laboratory (JHUAPL) MESSNEGER > Explore. Jan. 30, 2008.
Available @ https://messenger.jhuapl.edu/Explore/Science-Images-Database/gallery-image-154.html

MESSENGER. "New Names for Features on Mercury." Johns Hopkins University Applied Physics Laboratory (JHUAPL) MESSENGER > Explore. April 28, 2008.
Available @ https://messenger.jhuapl.edu/Explore/Science-Images-Database/gallery-image-181.html

Nemiroff, Robert; and Jerry Bonnell. "Unusual Hollows Discovered on Planet Mercury." NASA Astronomy Picture of the Day. March 27, 2012.
Available @ https://apod.nasa.gov/apod/ap120327.html

Prockter, Louise M.; Thomas R. Watters; Clark R. Chapman; Brett W. Denev; James W. Head III; Sean C. Solomon; Scott L. Murchie1; Olivier S. Barnouin-Jha; Mark S. Robinson; David T. Blewett; Jeffrey Gillis-Davis; and Robert W. Gaskell. "The Curious Case of Raditladi Basin." 40th Lunar and Planetary Science Conference, March 23-27, 2009, The Woodlands, Texas.
Available @ https://www.lpi.usra.edu/meetings/lpsc2009/pdf/1758.pdf

Robinson, Mark S. Robinson; Scott L. Murchie; David T. Blewett; Deborah L. Domingue; S. Edward Hawkins III; James W. Head; Gregory M. Holsclaw; William E. McClintock; Timothy J. McCoy; Ralph L. McNutt Jr.; Louise M. Prockter; Sean C. Solomon; and Thomas R. Watters. "Reflectance and Color Variations on Mercury: Regolith Processes and Compositional Heterogeneity." Science, vol. 321, issue 5885 (July 04, 2008): 66-69 DOI: 10.1126/science.1160080
Available @ https://science.sciencemag.org/content/321/5885/66

Strom, Robert G.; Clark R. Chapman; William J. Merline; Sean C. Solomon; and James W. Head. "Mercury Cratering Record Viewed From MESSENGER's First Flyby." Science, vol. 321, issue 5885 (July 4, 2008): 79-81. DOI: 10.1126/science.1159317
Available @ https://science.sciencemag.org/content/321/5885/79

U.S.G.S. Astrogeology Science Center. "Twelve New Names and a New Theme for Fossae Approved for Use on Mercury." USGS Astrogeology Science Center > News > Nomenclature News. April 9, 2008.
Available via USGS Astrogeology Science Center's Astropedia Web Portal @ https://astrogeology.usgs.gov/news/nomenclature/twelve-new-names-and-a-new-theme-for-fossae-approved-for-use-on-mercury