Earth and Space News: June 2012

Wednesday, June 27, 2012

De Morgan Crater Honors British Mathematician Augustus De Morgan

Summary: The lunar near side’s De Morgan Crater honors British mathematician Augustus De Morgan, who was a Fellow of the Royal Astronomical Society (FRAS).

Detail of Lunar Astronautical Chart (LAC) 60 shows De Morgan Crater in the lunar near side’s northeastern quadrant, to the west of Mare Tranquillitatis, to the southwest of Cayley Crater and to the northwest of Dionysius Crater; courtesy NASA (National Aeronautics and Space Administration) / GSFC (Goddard Space Flight Center) / ASU (Arizona State University): U.S. Geological Survey, Public Domain, via USGS Astrogeology Science Center / Gazetteer of Planetary Nomenclature

The lunar near side’s De Morgan Crater honors British mathematician Augustus De Morgan, who emphasized his interests in astronomy and mathematics via his membership in the Royal Astronomical Society (RAS) and the London Mathematical Society (LMS).

De Morgan Crater is a small lunar impact crater in the lunar near side’s northeastern quadrant. The nearly circular, bowl-shaped crater’s inner wall slopes conically to a small interior floor at the crater’s midpoint.

De Morgan is centered at 3.31 degrees south latitude, 14.89 degrees east longitude, according to the International Astronomical Union’s (IAU) Gazetteer of Planetary Nomenclature. The northern hemisphere crater registers northernmost and southernmost latitudes at 3.47 degrees north and 3.15 degrees north, respectively. The eastern hemisphere crater records easternmost and westernmost longitudes at 15.05 degrees east and 14.73 degrees east, respectively. De Morgan Crater has a small diameter of 9.68 kilometers.

Neighboring craters Cayley and Dionysius foil De Morgan’s easy visibility, according to Mark Tillotson and Jim Mosher’s The Moon Wiki. De Morgan’s unbright smallness cannot compete with bright, crisply-walled Cayley and bright-haloed, dark-rayed Dionysius.

Circular, bowl-shaped Cayley Crater lies to the northeast of De Morgan Crater. Cayley is centered at 3.94 degrees south latitude, 15.09 degrees east longitude. The highly reflective crater obtains northernmost and southernmost latitudes at 4.17 degrees north and 3.7 degrees north, respectively. Its easternmost and westernmost longitudes occur at 15.32 degrees east and 14.85 degrees east, respectively. Cayley Crater’s diameter measures 14.2 kilometers.

Dionysius Crater lies to the southeast of De Morgan Crater. Dionysius is centered at 2.77 degrees south latitude, 17.29 degrees east longitude. The conspicuous crater’s northernmost and southernmost latitudes are found at 3.06 degrees north and 2.49 degrees north, respectively. Its easternmost and westernmost longitudes occur at 17.58 degrees east and 17.01 degrees east, respectively. Dionysius Crater’s diameter spans 17.25 kilometers.

De Morgan lies to the west of Mare Tranquillitatis (Sea of Tranquility). The large, dark, basaltic plain has a famed association with Apollo 11. The National Aeronautics and Space Administration’s (NASA) first manned lunar landing mission landed in the lunar mare’s southwestern edge on Sunday, July 20, 1969. Statio Tranquillitatis (Tranquility Base) is located in southwestern Mare Tranquillitatis, to the southeast of De Morgan.

Mare Tranquillitatis is centered at 8.35 degrees south latitude, 30.83 degrees east longitude. The primarily northern crater marks northernmost and southernmost latitudes at 19.37 degrees north and minus 4.05 degrees south, respectively. The eastern hemisphere crater’s easternmost and westernmost longitudes stretch to 45.49 degrees east and 16.92 degrees east, respectively. Mare Tranquillitatis has a diameter of 875.75 kilometers.

De Morgan Crater received official name approval in 1935 during the International Astronomical Union’s (IAU) Vth (5th) General Assembly, held Wednesday, July 10, to Wednesday, July 17, in Paris, France. The crater honors Augustus De Morgan (June 27, 1806-March 18, 1871).

The 19th-century British mathematician’s memberships in the Royal Astronomical Society (RAS) and the London Mathematical Society (LMS) attested to his interests in astronomy and mathematics. In 1828 he became the first professor of mathematics at the newly established London University, now known as University College London (UCL). Apart from an absence from July 1831 to October 1836, De Morgan taught at London University until his retirement in 1866.

Two astronomy-themed works by De Morgan carefully demystified celestial globes and maps for novices. He published An Explanation of the Gnomonic Projection of the Sphere in 1836 and The Globes, Celestial and Terrestrial in 1845.

The takeaways for the lunar near side’s De Morgan Crater, which honors 19th-century British mathematician Augustus De Morgan, are that the bowl-shaped impact crater lies to the northwest of Apollo 11’s landing site in the near side’s northeastern quadrant; that the crater system’s namesake’s interests in astronomy and mathematics were evinced in his membership in the Royal Astronomical Society (RAS) and the London Mathematics Society (LMS); and that two astronomy works by the London University mathematics professor aimed to elucidate celestial globes and maps for novices.

Detail of Shaded Relief and Color-Coded Topography Map shows lunar near side’s De Morgan Crater (lower center) in terrain west of Mare Tranquillitatis: U.S. Geological Survey, 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:

Andersson, Leif E.; and Ewen A. Whitaker. NASA Catalogue of Lunar Nomenclature. NASA Reference Publication 1097. Washington DC: NASA National Aeronautics and Space Administration Scientific and Technical Information Branch, October 1982.
Available via NASA NTRS (NASA Technical Reports Server) @ https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19830003761.pdf

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

De Morgan, Augustus. Essays on the Life and Work of Newton. Edited, with notes and appendices, by Philip E.B. Jourdain. Chicago IL; London UK: The Open Court Publishing Company, 1914.
Available via Internet Archive @ https://archive.org/details/essaysonlifework00demorich/

De Morgan, Augustus. An Explanation of the Gnomonic Projection of the Sphere; and of Such Points of Astronomy as Are Most Necessary in the Use of Astronomical Maps: Being a Description of the Construction and Use of the Larger and Smaller Maps of the Stars; as Also of the Six Maps of the Earth. Published under the superintendence of The Society for the Diffusion of Useful Knowledge. London UK: Baldwin and Cradock, 1836.
Available via Internet Archive @ https://archive.org/details/explanationofgno00demorich/

De Morgan, Augustus. The Globes, Celestial and Terrestrial. London UK: Malby and Co., 1845.
Available via Internet Archive @ https://archive.org/details/globescelestial00morggoog

De Morgan, Sophia Elizabeth. Memoir of Augustus De Morgan. With Selections From His Letters. London UK: Longmans, Green, and Co., 1882.
Available via Internet Archive @ https://archive.org/details/memoirofaugustus00demorich/

Elger, Thomas Gwyn. “Cayley.” The Moon: A Full Description and Map of Its Principal Physical Features: 56. London UK: George Philip & Son, 1895.
Available via Internet Archive @ https://archive.org/details/moonfulldescript00elgerich/page/56

Elger, Thomas Gwyn. “De Morgan.” The Moon: A Full Description and Map of Its Principal Physical Features: 55. London UK: George Philip & Son, 1895.
Available via Internet Archive @ https://archive.org/details/moonfulldescript00elgerich/page/55

Elger, Thomas Gwyn. “Dionysius.” The Moon: A Full Description and Map of Its Principal Physical Features: 55. London UK: George Philip & Son, 1895.
Available via Internet Archive @ https://archive.org/details/moonfulldescript00elgerich/page/55

Higgitt, Rebekah. “Why I Don’t FRS My Tail: Augustus De Morgan and the Royal Society.” Notes and Records of the Royal Society of London, vol. 60, no. 3 (Sept. 22, 2006): 253-259.
Available via JSTOR @ https://www.jstor.org/stable/20462591

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Cayley.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > The Moon. Last updated Oct. 18, 2010.
Available @ https://planetarynames.wr.usgs.gov/Feature/1093

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “De Morgan.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > The Moon. Last updated Oct. 18, 2010.
Available @ https://planetarynames.wr.usgs.gov/Feature/1443

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Dionysius.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > The Moon. Last updated Oct. 18, 2010.
Available @ https://planetarynames.wr.usgs.gov/Feature/1542

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Mare Tranquillitatis.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > The Moon. Last updated Oct. 18, 2010.
Available @ https://planetarynames.wr.usgs.gov/Feature/3691

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Statio Tranquillitatis.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > The Moon. Last updated Oct. 25, 2010.
Available @ https://planetarynames.wr.usgs.gov/Feature/5684

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. “Maxwell Crater Honors Scottish Mathematical Physicist James Maxwell.” Earth and Space News. Wednesday, June 6, 2012.
Available @ https://earth-and-space-news.blogspot.com/2012/06/maxwell-crater-honors-scottish.html

Marriner, Derdriu. “Near Side Lunar Crater Swift Honors American Astronomer Lewis Swift.” Earth and Space News. Wednesday, Jan. 4, 2012.
Available @ https://earth-and-space-news.blogspot.com/2012/01/near-side-lunar-crater-swift-honors.html

Marriner, Derdriu. “Pogson Crater Honors British Astronomer Norman Robert Pogson.” Earth and Space News. Wednesday, June 20, 2012.
Available @ https://earth-and-space-news.blogspot.com/2012/06/pogson-crater-honors-british-astronomer.html

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

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

The Moon Wiki. “De Morgan.” The Moon > Lunar Features Alphabetically > D Nomenclature.
Available @ https://the-moon.us/wiki/De_Morgan

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

The Moon Wiki. “Mare Tranquillitatis.” The Moon > Lunar Features Alphabetically > T Nomenclature.
Available @ https://the-moon.us/wiki/Mare_Tranquillitatis

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

Stratton, F.J.M. (Frederick John Marrian), ed. Vth General Assembly Transactions of the IAU Vol. V B Proceedings of the 5th General Assembly Paris France, July 10-17, 1935. Cambridge UK: Cambridge University Press, Jan. 1, 1936.
Available @ https://www.iau.org/publications/iau/transactions_b/

Wednesday, June 20, 2012

Pogson Crater Parents Three Satellites in Mare Australe’s Eastern Edge

Summary: Pogson Crater parents three satellites in Mare Australe’s eastern edge in the lunar far side’s southwestern quadrant.

Pogson Crater parents three satellites in Mare Australe’s eastern edge as a mid-latitude crater system in the lunar far side’s southwestern quadrant.

The system’s parental crater is centered at minus 42.38 degrees south latitude, 111.11 degrees east longitude, according to the International Astronomical Union’s (IAU) Gazetteer of Planetary Nomenclature. The primary lunar impact crater registers northernmost and southernmost latitudes at minus 41.7 degrees south and minus 43.05 degrees south, respectively. Parental Pogson records easternmost and westernmost longitudes at 112.03 degrees east and 110.2 degrees east, respectively. Pogson Crater’s diameter measures 40.87 kilometers.

Pogson Crater parents three satellites. All three satellites are found to the east of their parent. C claims the closest position, lying to the northeast of its parent. G is located to the southeast of its parent and of C. Sited directly to the east, F logs the most distance from its parent.

Satellite F contrasts with C and G in the intricate swirl of its interior features. Ridgelike formations that extend from the crater’s inner walls distinguish the interior floor’s northwestern, northeastern and southeastern quadrants. Craterlets are strewn rather noticeably across the southwestern quadrant’s somewhat level floor. Craterlets also pock the other quadrants, with the largest conspicuously situated amid the northwestern quadrant’s ridges.

Pogson C is centered at minus 41.62 degrees south latitude, 112.24 degrees east longitude. Satellite C obtains northernmost and southernmost latitudes at minus 41.35 degrees south and minus 41.9 degrees south, respectively. Its easternmost and westernmost longitudes occur at 112.62 degrees east and 111.87 degrees east, respectively. The satellite’s diameter of 16.81 kilometers places C as the smallest of the Pogson system’s three satellites.

Pogson F is centered at minus 42.3 degrees south latitude, 115.42 degrees east longitude. Satellite F marks northernmost and southernmost latitudes at minus 41.73 degrees south and minus 42.86 degrees south, respectively. Its easternmost and westernmost longitudes are found at 116.19 degrees east and 114.66 degrees east, respectively. Satellite F’s diameter of 34.25 kilometers qualifies as Pogson F as the largest of the Pogson system’s three satellites.

Pogson G is centered at minus 42.96 degrees south latitude, 113.42 degrees east longitude. Satellite G’s northernmost and southernmost latitudes reach minus 42.41 degrees south and minus 43.51 degrees south, respectively. Its easternmost and westernmost longitudes extend to 114.17 degrees east and 112.67 degrees east, respectively. Satellite G has a diameter of 33.21 kilometers.

The Pogson Crater system occupies the eastern edge of the far side and near side’s shared southeastern basaltic plain, Mare Australe. The Southern Sea overlaps the moon’s eastern limb. The Pogson Crater system and the mid- to far regions of Mare Australe are found on the lunar far side, behind the near side’s southeastern limb.

Mare Australe is centered at minus 47.77 degrees south latitude, 91.99 degrees east longitude. The lunar mare’s northernmost and southernmost latitudes reach minus 31.84 degrees south and minus 64.2 degrees south, respectively. Its easternmost and westernmost longitudes stretch to 113.36 degrees east and 70.43 degrees east, respectively. Mare Australe’s diameter measures 996.84 kilometers.

The takeaways for the lunar far side’s Pogson Crater’s parentage of three satellites in Mare Australe’s eastern edge are that the Pogson system’s three satellites lie to the east of their parent; that the system’s most northerly, southerly and easterly placements are claimed by C, G and F, respectively; that Pogson F is the system’s largest satellite, with a diameter of 34.25 kilometers; that Pogson C is the system’s smallest satellite, with a diameter of 16.81 kilometers; that Pogson F exhibits the system’s most intricately featured interior; that Pogson C claims closest occupancy to its parent; and that Pogson F’s location logs the most distance from parental Pogson.

Detail of Lunar Astronautical Chart (LAC) 117 shows Pogson Crater system, comprising parental Pogson and trio of satellites Pogson C, Pogson G and Pogson F; courtesy NASA (National Aeronautics and Space Administration) / GSFC (Goddard Space Flight Center) / ASU (Arizona State University): U.S. Geological Survey, 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:

Detail of view of southwestern lunar far side shows Pogson Crater system, comprising parental Pogson Crater and trio of satellites C, F and G; frame M-121 image obtained Feb. 19, 1967, at 19:22 Universal Time, by Lunar Orbiter 3, from a distance of 1,500 kilometers and phase angle 70.19 degrees; blue arrow=Pogson Crater, yellow=Pogson C, green=Pogson F, red=Pogson G: Public Domain, via NASA GSFC (Goddard Space Flight Center) NSSDC (NASA Space Science Data Coordinated Archive) Catalog of Spaceborne Imaging @ https://nssdc.gsfc.nasa.gov/imgcat/html/object_page/lo3_m121.html

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

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. “Pogson.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > The Moon. Last updated Oct. 18, 2010.
Available @ https://planetarynames.wr.usgs.gov/Feature/4774

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Pogson C.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > The Moon. Last updated Oct. 18, 2010.
Available @ https://planetarynames.wr.usgs.gov/Feature/12166

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Pogson G.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > The Moon. Last updated Oct. 18, 2010.
Available @ https://planetarynames.wr.usgs.gov/Feature/12167

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Pogson F.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > The Moon. Last updated Oct. 18, 2010.
Available @ https://planetarynames.wr.usgs.gov/Feature/12168

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

Menzel, D.H. (Donald Howard); M. (Marcel) Minnaert; B. (Borris) Levin; A. (Audouin) Dollfus; and B. Bell. “Report on Lunar Nomenclature by The Working Group of Commission 17 of the IAU.” Space Science Reviews, vol. 12, issue 2 (1971): 136-186.
Available via Harvard ADSABS (NASA Astrophysics Data System Abstracts) @ http://adsabs.harvard.edu/full/1971SSRv...12..136M
Available via Harvard ADSABS (NASA Astrophysics Data System Abstracts) @ http://adsabs.harvard.edu/pdf/1971SSRv...12..136M

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

The Moon Wiki. “Mare Australe.” The Moon > Lunar Features Alphabetically > A Nomenclature.
Available @ https://the-moon.us/wiki/Mare_Australe

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

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

Shingareva, K. (Kira B.); and G. (George A.) Burba. The Lunar Nomenclature: The Reverse Side of the Moon (1961-1973). NASA Technical Memorandum TM-75035. Translation of Lunnaya Nomenklatura: Obratnaya Storona Luny 1961-1973. Washington DC: National Aeronautics and Space Administration, August 1977.
Available via NASA NTRS (NASA Technical Reports Server) @ https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19780004017.pdf

Williams, Dave; and Jay Friedlander. “Catalog of Spaceborne Imaging.” NASA GSFC (Goddard Space Flight Center) NSSDC (NASA Space Science Data Coordinated Archive) > Image Resources.
Available @ https://nssdc.gsfc.nasa.gov/imgcat/

Saturday, June 16, 2012

Internally Stressed, Response Growing, Wind Loaded Tree Strength

Summary: Sharon Lilly, Nelda Matheny and E. Thomas Smiley find that internally stressed, response growing, wind loaded tree strength defies tree failure.

Tree strength response of woundwood, which is produced as a response to cambial (tissue layer between inner bark and wood) damage, compartmentalizes tree decay by reinforcing large cavities; a protective screen preserves hard outer rim and protects the cavity: USDA Forest Service-Northeastern Area/USDA Forest Service/Bugwood.org, CC BY 3.0 United States, via Forestry Images

Internally stressed, response growing, wind loaded tree strength accounts for some trees surviving failure-worthy events, according to Tree Risk Assessment: Loads and Growth Response in the June 2012 issue of Arborist News.

Sharon Lilly of the International Society of Arboriculture, Nelda Matheny of HortScience, Inc., and E. Thomas Smiley of Bartlett Tree Research Laboratory begin with two formulas. Formula 1 calculates bending moment M from force F times lever arm distance D for the magnitude of lateral forces levering against the tree crown's center. Arborists describe load as resulting from "various forces acting on a structure" and designate gravity pulling downward and climbers, epiphytes, rigging operations and wind operating dynamically.

Downward and dynamic forces exert "stresses and strains in the tree structure" against which drag, as wind velocity squared, is "the most common, wind-related lateral force."

Winds flow more forcefully against taller trees and at higher altitudes even though drag functions under the influences of air density, wind resistance and wind-intercepting surfaces.

Greater streamlining-induced reconfigurations of branches, leaves and twigs on the wind-intercepting "frontal area and volume of crown facing the wind" go with more forceful wind speeds. Internal stresses from the loads of climbers, epiphytes, gravity, rigging operations and winds have a mathematical definition in Formula 2, whereby stress equals force over area. Stress involves separate, simultaneous or successive forces of compression squeezing tree fibers, shear sliding them in opposite side-by-side directions, tension stretching them and torsion twisting them.

Cross-sectional areas decreased by stress-raising cankers, notch cuts and sharp-angled bends join to overload, and overwhelm into failure, internally stressed, response growing, wind loaded tree strength.

Mass damping by different-sized branches, leaves and twigs moving helter-skelter and proximity to other trees keep loads less stressful by dissipating or transferring wind energy elsewhere.

Internally stressed, response growing, wind loaded tree strength leads to trees withstanding "stress without failure" while breaking stress lets others suffer "stress sufficient to cause failure." It makes possible such response growth potentials or presences as bulges, buttress roots, corrected leans, intact bark, pest-free crowns, ribs, taper and well-developed, wide root flares. Strong trees need to generate new wood, known as response growth, that responds to "damage or loads, which compensates for higher strain (deformation) in marginal fibers."

Species-specific amounts observe inputs from energy reserves and light, nutrient and water resources while response growth distribution overlaps with mechanical stress, repeated movement and structural weakness.

Internally stressed, response growing, wind loaded tree strength produces reaction wood "in response to a stimulus or load," such as growth from cuts and toward light.

Compression wood qualifies as reaction wood whose response growth patterns in conifers "is composed of cells that have expanded" to compensate for lower- or leeward-leaning stems. The type of reaction wood called tension wood reveals response growth patterns of cells contracted to compensate for a stem's "upper or windward side" in hardwoods. Woundwood strengthens cavities or wounds whose cambial damage stimulates chemically distinct, decay-resistant, dense wood and whose enlarged, inward-curling "ram's horns" support openings that cannot close over.

Response growth tells master arborists, master gardeners, master naturalists and tree stewards that tree strength may constitute "sufficient structural compensation" to avoid failure and survive overloads.

Young red pine (Pinus resinosa) displays snow pull damage on lower branches; strong, upper branches resisted the snow force: Steven Katovich, 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:

Woundwood, which is produced as a response to cambial (tissue layer between inner bark and wood) damage, compartmentalizes tree decay by reinforcing large cavities; a protective screen preserves hard outer rim and protects the cavity: USDA Forest Service-Northeastern Area/USDA Forest Service/Bugwood.org, CC BY 3.0 United States, via Forestry Images @ https://www.forestryimages.org/browse/detail.cfm?imgnum=1408012

Young red pine (Pinus resinosa) displays snow pull damage on lower branches; strong, upper branches resisted the snow force: Steven Katovich, CC BY 3.0 United States, via Forestry Images @ https://www.forestryimages.org/browse/detail.cfm?imgnum=1593060

For further information:

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

Smiley, E. Thomas; Matheny, Nelda; and Lilly, Sharon. June 2012. "Tree Risk Assessment: Loads and Growth Response." Arborist News 21(3): 12-16.
Available @ http://viewer.epaperflip.com/Viewer.aspx?docid=6e0f74c1-8c91-4709-94be-a2bd00ae9609#?page=12

Wednesday, June 13, 2012

Pogson Crater Honors British Astronomer Norman Robert Pogson

Summary: The lunar far side’s Pogson Crater honors British astronomer Norman Robert Pogson, Madras Observatory director and discoverer of eight asteroids.

Detail of Lunar Astronautical Chart (LAC) 117 shows Pogson Crater system, to the east of Mare Australe (Southern Sea), in the lunar far side’s southwestern quadrant; courtesy NASA (National Aeronautics and Space Administration) / GSFC (Goddard Space Flight Center) / ASU (Arizona State University): U.S. Geological Survey, Public Domain, via USGS Astrogeology Science Center / Gazetteer of Planetary Nomenclature

The lunar far side’s Pogson Crater honors British astronomer Norman Robert Pogson, who directed the British East India Company’s Madras Observatory for three decades and whose astronomical contributions include discovery of eight asteroids and formulation of Pogson’s ratio of stellar magnitude.

Circular Pogson Crater has a worn rim. A small craterlet perches on Pogson’s southern rim. A pair of craterlets occupy Pogson’s northeastern rim.

Pogson Crater is centered at minus 42.38 degrees south latitude, 111.11 degrees east longitude, according to the International Astronomical Union’s (IAU) Gazetteer of Planetary Nomenclature. The southern hemisphere crater records northernmost and southernmost latitudes at minus 41.7 degrees south and minus 43.05 degrees south, respectively. The eastern hemisphere crater registers easternmost and westernmost longitudes at 112.03 degrees east and 110.2 degrees east, respectively. Pogson Crater’s diameter spans 40.87 kilometers.

Pogson Crater is classified as a primary crater in the Pogson Crater system. The primary crater parents three satellites.

The three satellites are sited to the east of Pogson Crater. Pogson C’s northeastern position places makes it the closest to its parent. Next closest is southeastern-sited Pogson G. Pogson F, which is the most distant of the system’s satellites, lies directly east of its parent.

The Pogson Crater system lies to the east of Mare Australe (Southern Sea) in the lunar far side’s southwestern quadrant. The unevenly-surfaced, dark, basaltic plain extends over both the near side and the far side of Earth’s moon.

Mare Australe is centered at minus 47.77 degrees south latitude, 91.99 degrees east longitude. The lunar mare’s northernmost and southernmost latitudes stretch to minus 31.84 degrees south and minus 64.2 degrees south, respectively. It encounters easternmost and westernmost longitudes at 113.36 degrees east and 70.43 degrees east, respectively. Mare Australe’s length measures 996.84 kilometers.

Pogson Crater received official name approval in 1970 during the International Astronomical Union’s XIVth (14th) General Assembly, held Tuesday, Aug. 18, to Thursday, Aug. 27, in Brighton, United Kingdom. The IAU approved the designations for Pogson Crater system’s three satellites in 2006 during the organization’s XXVIth (26th) General Assembly, held Monday, Aug. 14, to Friday, Aug. 25, in Prague, Czech Republic.

Pogson Crater’s formal name honors Norman Robert Pogson (March 23, 1829-June 23, 1891). The 19th-century British astronomer served as director of the British East India Company’s Madras Observatory for three decades, from 1861 until his death. His accomplishments as an observational astronomy included discovering 13 variable stars and eight asteroids.

Pogson clinched his first asteroid find with his May 23, 1856, discovery of 42 Isis, from the Radcliffe Observatory in Oxford, Oxfordshire, South East England. His second and third asteroid discoveries, 43 Ariadne and 46 Hestia, were achieved from the Radcliffe Observatory in 1857, on April 15 and Aug. 16, respectively.

Pogson discovered his fourth asteroid, 67 Asia, on April 17, 1861. The bright asteroid numbered as his first asteroid discovery at southeastern India’s Madras Observatory.

Tamil Nadu state’s Madras Observatory also is credited as the observing site for his fifth through eighth asteroids. He claimed 80 Sappho as his fifth asteroid on May 2, 1864. He espied 87 Sylvia on May 16, 1866. He discovered his seventh asteroid, 107 Camilla, on Nov. 17, 1868, and his eighth, 245 Vera, on Feb. 6, 1885.

Pogson is also credited with formulating a mathematical scale of stellar magnitudes in which the ratio of two successive magnitudes equates to the fifth root of 100 (100^1/5). Each magnitude is defined at 100 times the brightness of its predecessor. Pogson’s formula is known as Pogson’s ratio.

The takeaways for the lunar far side’s Pogson Crater, which honors 19th-century British astronomer Norman Robert Pogson, are that the worn, circular crater parents three satellites in the far side’s southwestern quadrant, to the east of Mare Australe (Southern Sea); that the crater system’s namesake was the Government astronomer of southeastern India’s Madras Observatory; and that Norman Pogson’s astronomical contributions include discovering eight asteroids and 13 variable stars and formulating Pogson’s ratio of stellar magnitude.

Detail of Shaded Relief and Color-Coded Topography Map shows Pogson Crater system in the lunar far side’s southeastern quadrant: U.S. Geological Survey, 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:

Detail of Lunar Astronautical Chart (LAC) 117 shows Pogson Crater system, to the east of Mare Australe (Southern Sea), in the lunar far side’s southeastern quadrant; courtesy NASA (National Aeronautics and Space Administration) / GSFC (Goddard Space Flight Center) / ASU (Arizona State University): U.S. Geological Survey, Public Domain, via USGS Astrogeology Science Center / Gazetteer of Planetary Nomenclature @ https://planetarynames.wr.usgs.gov/images/Lunar/lac_117_wac.pdf

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

de Jager, C.; and A. (Arnost) Jappel, eds. XIVth General Assembly Transactions of the IAU Vol. XIV B Proceedings of the 14th General Assembly Brighton, United Kingdom, August 18-27, 1970. Washington DC: Association of Universities for Research in Astronomy, Jan. 1, 1971.
Available @ https://www.iau.org/publications/iau/transactions_b/

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

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

The Moon Wiki. “Mare Australe.” The Moon > Lunar Features Alphabetically > A Nomenclature.
Available @ https://the-moon.us/wiki/Mare_Australe

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

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

Nautical Almanac Offices of the United Kingdom and the United States of America. Explanatory Supplement to the Astronomical Ephemeris and the American Ephemeris and Nautical Almanac. London UK: Her Majesty’s Stationery Office, 1961.
Available via Internet Archive @ https://archive.org/details/astronomicalalmanac1961/

P., W.E. “Norman R. Pogson, C.I.E.” Nature > News. July 2, 1891.
Available @ https://www.nature.com/articles/044205c0

Pogson, Norman. “Magnitudes of Thirty-Six of the Minor Planets for the First Day of Each Month of the Year 1857.” Monthly Notices of the Royal Astronomical Society, vol. 17, issue 1 (November 1856): 12-15.
Available via OUP (Oxford University Press) Academic @ https://academic.oup.com/mnras/article/17/1/12/956950

van der Hucht, Karel A., ed. XXVIth General Assembly Transactions of the IAU Vol. XVII B Proceedings of the 26th General Assembly Prague, Czech Republic, August 14-25, 2006. Cambridge UK: Cambridge University Press, Dec. 30, 2008.
Available @ https://www.iau.org/publications/iau/transactions_b/

Wednesday, June 6, 2012

Maxwell Crater Honors Scottish Mathematical Physicist James Maxwell

Summary: The lunar far side’s Maxwell Crater honors Scottish mathematical physicist James Maxwell, who explored electromagnetic radiation and Saturn’s rings.

Detail of Near Side Shaded Relief and Color-Coded Topography shows Maxwell Crater (upper center) with overlapped northern neighbor Richardson and overlapping southern neighbor Lomonosov in the lunar near side’s northwestern quadrant: U.S. Geological Survey, Public Domain, via USGS Astrogeology Science Center / Gazetteer of Planetary Nomenclature

The lunar far side’s Maxwell Crater honors Scottish mathematical physicist James Maxwell, whose astronomical contributions included research in electromagnetic radiation and proving the particulate nature of Saturn’s rings.

Erosion roughens the circularity of Maxwell Crater’s generally uneven rim. The interior floor’s levelness contrasts with the crater’s degraded rim.

Maxwell Crater is centered at 29.9 degrees north latitude, 98.53 degrees east longitude, according to the International Astronomical Union’s (IAU) Gazetteer of Planetary Nomenclature. The northern hemisphere crater registers northernmost and southernmost latitudes at 31.71 degrees north and 28.1 degrees north, respectively. The eastern hemisphere crater records easternmost and westernmost longitudes at 100.6 degrees east and 96.45 degrees east, respectively. Maxwell Crater’s diameter spans 109.24 kilometers.

The far side crater occupies a substantial portion of the southwestern part of Richardson Crater. Maxwell Crater intrudes across Richardson’s rim and overlies nearly half of Richardson’s interior floor with its outer rampart. Maxwell’s northeastern rim marks Richardson’s approximate midpoint.

Richardson Crater is centered at 30.93 degrees south latitude, 99.89 degrees east longitude. The large impact crater’s northernmost and southernmost latitudes occur at 33.63 degrees north and 28.27 degrees north, respectively. Richardson obtains easternmost and westernmost longitudes at 103.06 degrees east and 96.8 degrees east, respectively. Richardson’s diameter measures 162.56 kilometers.

While Maxwell Crater extensively superimposes northern neighbor Richardson, its southern portion is overwhelmed by southern neighbor Lomonosov. Resurfacing by lava flows has darkened Lomonosov’s dark, level interior floor.

Lomonosov Crater is centered at 27.35 degrees south latitude, 98.28 east longitude. The northern hemisphere impact crater’s northernmost and southernmost latitudes reach to 28.85 degrees north and 25.85 degrees north, respectively. Its easternmost and westernmost longitudes extend to 99.96 degrees east and 96.59 degrees east, respectively. Lomonosov Crater has a diameter of 90.69 kilometers.

Maxwell Crater lies to the northeast of Mare Marginis (Sea of the Edge). The dark, basaltic plain is found along the far side’s eastern limb.

Mare Marginis is centered at 12.7 degrees south latitude, 86.52 degrees east longitude. The irregularly shaped lunar mare records northernmost and southernmost latitudes at 18.59 degrees north and 9.81 degrees north, respectively. Easternmost and westernmost longitudes are found at 93.35 degrees east and 81.15 degrees east. Mare Marginis has a diameter of 357.63 kilometers.

Maxwell Crater received official name approval in 1961 at the International Astronomical Union’s XIth (11th) General Assembly, held Tuesday, Aug. 15, to Thursday, Aug. 24, in Berkeley, California. Prior to its formal naming, Maxwell Crater was identified as Crater 112.

Maxwell Crater honors 19th-century Scottish mathematical physicist James Clerk Maxwell (June 13, 1831-Nov. 5, 1879). In a tribute in Cambridge University’s commemorative volume on the centenary of Maxwell’s birth, German-born theoretical physicist Albert Einstein (March 14, 1879-April 18, 1955) recognized the significance of researches on electromagnetism by Maxwell and by 19th-century English chemist and physicist Michael Faraday (Sept. 22, 1791-Aug. 25, 1867). “The greatest alteration in the axiomatic basis of physics --- in our conception of the structure of reality -- since the foundation of theoretical physics by Newton, originated in the researches of Faraday and Maxwell on electromagnetic phenomena” (pages 66-67).

Maxwell’s scientific contributions also included studying Saturn’s rings. His determination of the particulate nature of Saturn’s rings, published in 1859, was confirmed by the Voyager 1 and 2 flybys in 1980 and 1981, respectively.

The formal naming of Maxwell Crater’s southern neighbor, Lomonosov Crater, also occurred in 1961. Lomonosov Crater honors 18th-century Russian scientist, grammarian, mosaicist and writer Mikhail Vasilievich Lomonosov (Nov. 19, 1711-April 15, 1765).

Maxwell Crater’s northern neighbor, Richardson Crater, received official name approval in 1979 during the IAU’s XVIIth (17th) General Assembly, held Tuesday, Aug. 14, to Thursday, Aug. 23, in Montreal, Canada. Richardson Crater’s namesake is Sir Owen Willans Richardson (April 26, 1879-Feb. 15, 1959). The British quantum physicist received a Nobel Prize in Physics in 1928 for his research on thermionic emission, temperature-based release of electrons from an electrode, and for his associated discovery of the formula named after him, Richardson’s Law.

The takeaways for the lunar far side’s Crater Maxwell, which honors 19th-century Scottish mathematical physicist James Clerk Maxwell, are that the fairly circular, smooth-floored crater was identified as Crater 112 prior to its formal naming in 1961; that Maxwell superimposes its larger, northern neighbor, Richardson Crater, and is overlain by its smaller, southern neighbor, Lomonosov Crater; and that Maxwell’s namesake was esteemed by 20th-century genius Albert Einstein for his research on electromagnetism.

Oblique view, obtained by Apollo 16 mission, shows the lunar far side’s Maxwell Crater (center), overlapped by southern neighbor Lomonosov (lower left); NASA ID AS16-M-3008: Apollo Image Archive, NASA / JSC (Johnson Space Center) / Arizona State University: Jstuby (James L. Stuby), Public Domain (CC0 1.0), 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:

Detail of Near Side Shaded Relief and Color-Coded Topography shows Maxwell Crater (upper center) with overlapped northern neighbor Richardson and overlapping southern neighbor Lomonosov in the lunar near side’s northeastern quadrant: U.S. Geological Survey, Public Domain, via USGS Astrogeology Science Center / Gazetteer of Planetary Nomenclature @ https://planetarynames.wr.usgs.gov/images/moon_farside.pdf

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Available via Google Books @ https://books.google.com/books?id=zzYOP1EXyroC

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Available @ https://physicsworld.com/a/james-clerk-maxwell-a-force-for-physics/

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Available @ https://planetarynames.wr.usgs.gov/Feature/3462

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Mare Marginis.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > The Moon. Last updated Oct. 18, 2010.
Available @ https://planetarynames.wr.usgs.gov/Feature/3681

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Maxwell.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > The Moon. Last updated Oct. 18, 2010.
Available @ https://planetarynames.wr.usgs.gov/Feature/3765

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Richardson.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > The Moon. Last updated Oct. 18, 2010.
Available @ https://planetarynames.wr.usgs.gov/Feature/5027

James Clerk Maxwell Foundation. “The Impact of Maxwell’s Work: Between Newton and Einstein, James Clerk Maxwell Stands Alone.” James Clerk Maxwell Foundation > About Maxwell.
Available @ http://www.clerkmaxwellfoundation.org/html/maxwell-s_impact_.html

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Maxwell, J. (James) Clerk. On the Stability of the Motion of Saturn’s Rings. An Essay, Which Obtained the Adams Prize for the Year 1856, in the University of Cambridge. Cambridge UK: Macmillan and Co., 1859.
Available via Internet Archive @ https://archive.org/details/onstabilityofmot00maxw/

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

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

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

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

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Available via Internet Archive @ https://archive.org/details/scientificpapers01maxw/

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Available via Google Books @ https://books.google.com/books?id=JZQRBwAAQBAJ

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Available @ https://www.iau.org/publications/iau/transactions_b/