Earth and Space News: April 2012

Wednesday, April 25, 2012

Vestine Crater Honors American Geophysicist Ernest Harry Vestine

Summary: The lunar far side’s Vestine Crater honors American geophysicist Ernest Harry Vestine, whose research interests included geomagnetism and noctilucent clouds.

Details of Lunar Astronautical Charts (LAC) 29 shows the Vestine Crater system in the lunar far side’s northwestern 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 Vestine Crater honors American geophysicist Ernest Harry Vestine, whose geophysical and meteorological research interests included geomagnetism and noctilucent clouds.

Vestine Crater is a greatly eroded lunar impact crater in the lunar far side’s northwestern quadrant. A rounded ridge approximately marks the crater’s midpoint. The relatively smooth interior floor is speckled with small craterlets and at least three larger craterlets.

Vestine is centered at 33.87 degrees south latitude, 93.68 degrees east longitude, according to the International Astronomical Union’s (IAU) Gazetteer of Planetary Nomenclature. The northern hemisphere crater obtains northernmost and southernmost latitudes at 35.48 degrees north and 32.26 degrees north, respectively. The primary crater’s easternmost and westernmost longitudes occur at 95.62 degrees east and 91.74 degrees east, respectively. Vestine Crater’s diameter spans 97.81 kilometers.

Vestine Crater members in the Vestine Crater system as a primary crater credited with two satellites. The parent neighbors its satellites. Vestine T projects off its parent’s northwestern rim, which covers the satellite’s eastern half. Vestine A claims proximitous placement near its parent’s north-northeastern rim.

Vestine A is centered at 36.02 degrees south latitude, 94.57 degrees east longitude. The satellite records northernmost and southernmost latitudes at 35.31 degrees north and 35.73 degrees north, respectively. It registers easternmost and westernmost longitudes at 94.93 degrees east and 94.21 degrees east, respectively. Vestine A has a diameter of 17.58 kilometers.

Vestine A lies between its parent and Harkhebi, its parent’s north-northeastern primary neighbor. Harkhebi is centered at 40.87 degrees north latitude, 98.74 degrees east longitude. The impact-riddled crater posts northernmost and southernmost latitudes of 46.36 degrees north and 35.34 degrees north, respectively. The large lunar impact crater’s easternmost and westernmost longitudes stretch from 104.6 degrees east to 92.94 degrees east, respectively. Harkhebi dwarfs satellite A’s parent with a diameter of 337.14 kilometers.

Vestine T is centered at 33.64 degrees south latitude, 91.05 degrees east longitude. Its northernmost and southernmost latitudes reach 34.54 degrees north and 32.73 degrees north, respectively. Its easternmost and westernmost longitudes extend to 91.99 degrees east and 90.11 degrees east, respectively. Vestine T’s diameter of 59.2 kilometers qualifies it as the larger of the Vestine Crater system’s two satellites. Satellite T’s diameter almost approximates 61 percent of its parent’s diameter of 97.81 kilometers.

The Vestine Crater system occupies the lunar far side’s northwestern quadrant. The parent and its two satellites lie to the north-northeast of lunar-limb straddling Mare Marginis. The Sea of the Edge wraps around the near side’s eastern limb to extend its eastern reaches into the far side.

The irregularly-outlined Mare Marginis is centered at 12.7 degrees south latitude, 86.52 degrees east longitude. The dark basaltic plain’s northernmost and southernmost latitudes extend from 1839 degrees north to 9.81 degrees north, respectively. Its easternmost and westernmost longitudes stretch from 93.35 degrees east to 81.15 degrees east, respectively. The Sea of the Edge’s diameter spans 357.63 kilometers.

The Vestine Crater system honors American geophysicist Ernest Harry Vestine (May 9, 1906-Juy 18, 1968). The International Astronomical Union approved the primary crater’s official name in 1970 during the organization’s XIVth (14th) General Assembly, which was held from Tuesday, Aug. 18, to Thursday, Aug. 27, in the seaside resort of Brighton in South East England. The Vestine Crater system’s two satellites received their official designations in 2006.

American astronomer, geophysicist and physicist Scott Ellsworth Forbush (April 10, 1904-April 4, 1984) recognized Vestine’s critical contributions to geomagnetism with his co-authorships of The Description of the Earth’s Main Magnetic Field and Its Secular Change, 1905-1945 and The Geomagnetic Field, Its Description and Analysis. Both volumes, published by the Carnegie Institution of Washington in 1947, systematized four decades of geomagnetic data. Vestine worked in the Carnegie Institution’s Department of Terrestrial Magnetism from 1938 to 1956.

Earlier in his career, Vestine pursued his interest in the upper atmosphere’s noctilucent, or night-shining, clouds. During the Second International Polar Year (IPY), which took place from 1932 to 1933, Vestine was stationed at the Meanook Magnetic Observatory in northern Alberta, Canada. He published his authoritative findings in 1934 in the Journal of the Royal Astronomical Society of Canada.

The takeaways for the lunar far side’s Vestine Crater, which honors 20th-century American geophysicist Ernest Harry Vestine, are that the primary lunar impact crater parents two satellites, Vestine A and Vestine T; that the Vestine Crater system occupies the northwestern quadrant, to the north-northeast of lunar limb straddling Mare Marginis; and that the crater’s namesake’s scientific contributions included a two-volume publication on Earth’s magnetism and meteorological studies of noctilucent clouds.

Detail of oblique view, obtained during Apollo 16 mission, shows Vestine Crater (center) with Vestine T (upper left) and Vestine A (upper right); NASA ID AS16-M-3008: James Stuby (Jstuby), 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 oblique view, during Apollo 16 mission, shows Vestine Crater (center) with Vestine T (upper left) and Vestine A (upper right); NASA ID AS16-M-3008: James Stuby (Jstuby), Public Domain (CC0 1.0), via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:Vestine_crater_AS16-M-3008_ASU.jpg

For further information:

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

de Jager, C. (Cornelis); 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/

Forbush, Scott E. “Ernest Harry Vestine.” 366-385. In: National Academy of Sciences of the United States of America. Biographical Memoirs, vol. 51. Washington DC: National Academy of Sciences, 1980.
Available via NAP (National Academies Press) @ https://www.nap.edu/download/574

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

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “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. “Harkhebi.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > The Moon. Last updated Oct. 18, 2010.
Available @ https://planetarynames.wr.usgs.gov/Feature/2365

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

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Vestine.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > The Moon. Last updated Oct. 18, 2010.
Available @ https://planetarynames.wr.usgs.gov/Feature/6369

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Vestine A.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > The Moon. Last updated Oct. 18, 2010.
Available @ https://planetarynames.wr.usgs.gov/Feature/13676

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Vestine T.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > The Moon. Last updated Oct. 18, 2010.
Available @ https://planetarynames.wr.usgs.gov/Feature/13677

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

Marriner, Derdriu. “Richardson Crater Honors British Physicist Sir Owen Willans Richardson.” Earth and Space News. Wednesday, April 11, 2012. Available @ https://earth-and-space-news.blogspot.com/2012/04/richardson-crater-honors-british.html

Marriner, Derdriu. “Richardson Crater Parents Two Satellites on Lunar Far Side.” Earth and Space News. Wednesday, April 18, 2012. Available @ https://earth-and-space-news.blogspot.com/2012/04/richardson-crater-parents-two.html

Menzel, D.H. (Donald Howard); M. (Marcel) Minnaert; B. (Borris) Levin; A. (Audouin) Dollfus; and B. (Barbara) Bell. “Report on Lunar Nomenclature by the Working Group of Commission 17 of The IAU.” Space Science Reviews, vol. 12, issue 2 (June 1971): 136-186.
Available via Springer Link @ https://link.springer.com/article/10.1007/BF00171763

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

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

The Moon Wiki. “Mare Marginis.” The Moon > Lunar Features Alphabetically > S Nomenclature.
Available @ https://the-moon.us/wiki/Mare_Marginis

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

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

Vestine, E.H. (Ernest Harry). “Nocticulent Clouds (With Plate VI).” Journal of the Royal Astronomical Society of Canada, vol. 28 (1934): 249-272, 303-317.

Vestine, E.H. (Ernest Harry); Lucile Laporte; Caroline Cooper; Isabelle Lange; and W.C. Hendrix. Description of the Earth’s Main Magnetic Field and its Secular Change, 1905-1945. Carnegie Institution of Washington Publication 578. Washington DC: Carnegie Institution of Washington, March 1947.
Available via Internet Archive @ https://archive.org/details/descriptionearth00carn/

Vestine, E.H. (Ernest Harry); Lucile Laporte; Isabelle Lange; and W.E. Scott. The Geomagnetic Field, Its Description and Analysis. Carnegie Institution of Washington Publication 580. Washington DC: Carnegie Institution of Washington, December 1947.
Available via Internet Archive @ https://archive.org/details/geomagneticfield00carn/

Wednesday, April 18, 2012

Richardson Crater Parents Two Satellites on Lunar Far Side

Summary: Richardson Crater parents two satellites on the lunar far side, in the crater-jumbled area northeast of Mare Marginis (Sea of the Edge).

Detail of oblique, northwestward view, obtained February 1971 with 70mm Hasselblad camera during Apollo 14 mission shows Maxwell Crater (center left) nestled on Richardson Crater (center) with Richardson E (center right) and Richardson W (upper center); NASA ID AS14-71-9852: James Stuby (Jstuby), Public Domain (CC0 1.0), via Wikimedia Commons

Richardson Crater parents two satellites on the lunar far side, in the northwest quadrant's crater-jumbled area northeast of Mare Marginis (Sea of the Edge).

Primary lunar impact crater Richardson is centered at 30.93 degrees south latitude, 99.89 degrees east longitude, according to the International Astronomical Union’s (IAU) Gazetteer of Planetary Nomenclature. Its northernmost and southernmost latitudes reach 33.63 degrees north and 28.27 degrees north, respectively. Its easternmost and westernmost longitudes extend to 103.06 degrees east and 96.8 degrees east, respectively. Richardson’s diameter measures 162.56 kilometers.

Richardson Crater serves as the parental crater in the Richardson Crater system. The large crater parents two satellites, Richardson E and Richardson W.

Richardson E is found near its parent’s eastern rim. The eastern satellite is centered at 32.01 degrees south latitude, 103.61 degrees east longitude. Its northernmost and southernmost latitudes occur at 32.36 degrees north and 31.65 degrees north, respectively. It registers easternmost and westernmost longitudes at 104.08 degrees east and 103.14 degrees east, respectively. Richardson E has a diameter of 24.14 kilometers.

Richardson E hunkers in proximity to the southwestern rim of its eastern neighbor, Szilard Crater. Primary lunar impact crater Szilard is centered at 33.71 degrees south latitude, 105.78 degrees east longitude. Szilard marks northernmost and southernmost latitudes at 35.8 degrees north and 31.61 degrees north, respectively. It obtains easternmost and westernmost longitudes at 108.3 degrees east and 103.26 degrees east, respectively. Szilard Crater’s diameter spans 127.22 kilometers.

Richardson W adjoins its parent’s northwestern rim. The western satellite is centered at 33.59 degrees south latitude, 98.34 degrees east longitude. It registers northernmost and southernmost latitudes at 33.98 degrees north and 33.21 degrees north, respectively. It records easternmost and westernmost longitudes at 98.8 degrees east and 97.88 degrees east, respectively. Richardson W’s diameter of 23.35 kilometers qualifies it as the smaller of its parent’s two satellites.

Richardson W’s nearest named primary craterous neighbors are Maxwell and Vestine. Maxwell lies to the south of satellite W. Vestine is sited to the west of Richardson W.

Maxwell Crater substantially overlies the southwestern portion of Richardson W’s parent. Maxwell is centered at 29.9 degrees north latitude, 98.53 east longitude. Maxwell Crater posts northernmost and southernmost latitudes of 31.71 degrees north and 28.1 degrees north, respectively. Its easternmost and westernmost longitudes occur at 100.6 degrees east and 96.45 degrees east, respectively. Maxwell Crater has a diameter of 109.24 kilometers.

Vestine Crater is centered at 33.87 degrees south latitude, 93.68 degrees east longitude. Vestine’s northernmost and southernmost latitudes extend to 35.48 degrees north and 32.26 degrees north, respectively. Its easternmost and westernmost longitudes reach 95.62 degrees east and 91.74 degrees east, respectively. Vestine Crater’s diameter measures 97.81 kilometers.

Swedish astronomer Leif Erland Andersson (Nov. 4, 1943-May 4, 1979) and British-born astronomer Ewen Adair Whitaker (June 22, 1922-Oct. 11, 2016) explained the assignment of far side satellite crater designations in their 1982 publication, NASA Catalogue of Lunar Nomenclature. “The letter designation scheme for the farside was devised for maximum ease in locating craters on maps, and works as follows: each ‘patronymic’ crater is considered to be the center of a 24 hour clockface in which the numbers have been replaced with Roman capital letters (I and O omitted, 24 h. = Z), with Z at the north point,” Andersson and Whitaker stated (page 6).

According to the 24-hour clockface of Roman capital letters, Z claims the position of 12 at the clockface’s top. A clockwise circuit finds B in the position of 1; D at 2; F at 3, H at 4; K at 5. M claims the bottom of the clockface, opposite 12, in the position of 6. P occupies 7’s spot; R is at 8. In the position of number 9 opposes F in number 3’s slot. V is at 10; X is at 11.

Andersson and Whitaker revealed the astronomy behind the clockface’s letter designations. “Thus each letter represents a fixed azimuth from the patronymic crater, and the chosen subsidiary craters are lettered according to their closest azimuths.”

The azimuth signifies the angle between a celestial body, such as the moon, and north, according to a clockwise measurement around the observer’s horizon. Richardson E’s designation indicates the satellite’s east-northeasterly position in the Richardson Crater system. Richardson W’s designation reveals the satellite’s northwesterly position in the Richardson Crater system.

The takeaways for Richardson Crater’s parentage of two satellites in the lunar far side are that Richardson E and Richardson W are positioned, respectively, to their parent’s east and northwest; that satellite E occupies a close location between its parent and eastern neighbor Szilard; and that satellite W intrudes into its parent’s northwestern rim.

Detail of Shaded Relief and Color-Coded Topography Map shows lunar far side’s Richardson Crater (upper right), with unmarked Richardson E (upper right) and W (upper center), to the northeast of Mare Marginis in the northwestern 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:

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.

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

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “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

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Richardson E.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > The Moon. Last updated Oct. 18, 2010.
Available @ https://planetarynames.wr.usgs.gov/Feature/12601

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Richardson W.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > The Moon. Last updated Oct. 18, 2010.
Available @ https://planetarynames.wr.usgs.gov/Feature/12602

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Szilard.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > The Moon. Last updated Oct. 18, 2010.
Available @ https://planetarynames.wr.usgs.gov/Feature/5799

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

Marriner, Derdriu. "Richardson Crater Honors British Physicist Sir Owen Willans Richardson." Earth and Space News. Wednesday, April 11, 2012.
Available @ https://earth-and-space-news.blogspot.com/2012/04/richardson-crater-honors-british.html

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

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

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

Saturday, April 14, 2012

Three Tree Risk Assessment Levels: Limited Visual, Basic and Advanced

Summary: Sharon Lilly, Nelda Matheny and E. Thomas Smiley hinge three tree risk assessment levels -- limited visual, basic, advanced -- on Scope of Work statements.

Scope of Work statements prior to visual, basic and advanced tree risk assessments describe the trees under assessment and the level of risk of assessment to be conducted; scenario of rotten tree fallen on house: Paul A. Mistretta/USDA Forest Service, CC BY 3.0 United States, via Forestry Images

Limited visual, basic and advanced tree risk assessment levels are preceded by Scope of Work statements, according to Tree Risk Assessment: Levels of Assessment in the April 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 work statements. Scope of Work statements confirm the client's budget, the local authority's inspection, permit and report requirements, the property's unrestricted access points and the written report's recipients. They describe the areas or trees to be assessed, the level to be conducted and target specifications for branch diameter, lean, live crown ratio and taper.

Work scope statements elucidate methods of reporting, needs for documentation and timetables for inspections and reports as well as ratings of risks and recommendations for mitigation.

Limited visual assessments through drive-by, fly-by or walk-by fit in as the first and "fastest but least thorough" level in the three tree risk assessment levels. They give their inspectors opportunities to assess "large populations of trees" after storms and for "obvious defects," specified conditions and "imminent and/or probable likelihood of failure." They hold status as inventories of conditions and defects for specific tree locations, sizes and species unless individualized, tree-by-tree analyses and evaluations meet risk assessment criteria.

Limited visual assessments include such "obvious defects" as "dead trees, large cavity openings, large dead or broken branches, fungal fruiting structures, large cracks, and severe leans."

"[C]ertain conditions of concern, such as lethal pests or symptoms associated with root decay" join specified concerns to be eyeballed behind windshields, from above or in-person.

Level 1 assessments keep "large populations of trees" inspected by agencies, landowners and municipalities on limited budgets and by utilities wary of electric transmission system threats.

The basic assessment process, as the second of three tree risk assessment levels, lets the inspector do a careful, complete walkabout of one tree or more. Level 2 inspectors make "detailed visual" inspections of the individual tree's branches, buttress roots and trunk and of the surrounding site, for hidden and obvious defects. They need no tools unless the Scope of Work permits binoculars, cavity probes, clinometers, diameter tapes, hand-held magnifying glasses, root-excavating trowels, tape measures or trunk-sounding mallets.

Basic assessors observe such above-ground, external, lower-crown factors as cavities, cracks, dead bark, decay, fungal fruiting bodies, hollows, nesting holes, pests, response growth and weak unions.

Advanced assessments, as the most expensive and intensive of three tree risk assessment levels, "provide detailed information about specific tree parts, defects, targets, or site conditions."

Aerial inspections by climbs, ladders or lifts, decay testing, soil profiling, storm/wind load analyses, tree ring analyses and trunk lean measurements qualify as advanced assessment techniques. The most sophisticated, "[s]pecialized equipment, data collection and analysis, and/or expertise" result in "a qualified estimation," not "an accurate measure," of below-ground, external and upper-crown factors. Cavities, cracks, decay and embedded bark sound differently than functional wood during full-fluted and resistance-recording drilling, in wood stress wave analyses, and on time-of-travel-generated multi-dimensional tomograms.

Assessors throw caution to the wind when their tools breach a tree's outer tracheid, inner latewood ring and radial xylem parenchyma and innermost new xylem walls.

Sonic tomography instruments are useful in tree risk assessment by helping arborists to detect decay: Joseph O'Brien/USDA Forest Service/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:

Sonic tomography instruments are useful in tree risk assessment by helping arborists to detect decay: Joseph O'Brien/USDA Forest Service/Bugwood.org, CC BY 3.0 United States, via Forestry Images @ https://www.forestryimages.org/browse/detail.cfm?imgnum=5034033

For further information:

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

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

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. April 2012. "Tree Risk Assessment: Levels of Assessment." Arborist News 21(2): 12-20.
Available @ http://viewer.epaperflip.com/Viewer.aspx?docid=632bea95-6e56-46d2-a603-a2bc00f42840#?page=12

Wednesday, April 11, 2012

Richardson Crater Honors British Physicist Sir Owen Willans Richardson

Summary: The lunar far side’s Richardson Crater honors British physicist Sir Owen Willans Richardson, 1928 Nobel Prize awardee for thermionic emission research.

Details of Lunar Astronautical Charts (LAC) 29 (above) and 46 (below) show the Richardson Crater system in the lunar far side’s northwestern 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 Richardson Crater honors British physicist Sir Owen Willans Richardson, whose 1928 Nobel Prize recognized his research on thermionic emission, the temperature-effected release of electrons by hot metals.

Richardson Crater occupies the lunar far side’s northwestern quadrant, beyond the near side’s eastern limb. It lies to the northeast of the near side eastern limb-straddling Mare Marginis (Sea of the Edge).

Mare Marginis is centered at 12.7 degrees north latitude, 86.52 degrees east longitude, according to the International Astronomical Union’s (IAU) Gazetteer of Planetary Nomenclature. It records northernmost and southernmost latitudes of 18.59 degrees north and 9.81 degrees north, respectively. The lunar mare posts easternmost and westernmost longitudes of 93.35 degrees east and 81.15 degrees east, respectively. Mare Marginis has a diameter of 357.63 kilometers.

The large lunar impact crater’s rim is eroded and worn. Craterlets pockmark Richardson’s relatively level interior floor.

Richardson Crater is centered at 30.93 degrees south latitude, 99.89 degrees east longitude. The northern hemisphere crater’s northernmost and southernmost latitudes reach 33.63 degrees north and 28.27 degrees north, respectively. The eastern hemisphere crater’s easternmost and westernmost longitudes extend to 103.06 degrees east and 96.8 degrees east, respectively. The far side crater’s diameter spans 162.56 kilometers.

Richardson Crater participates in a chain of overlapping craters. Richardson underlies Maxwell Crater, which, in turn, Lomonosov intrudes.

Maxwell Crater covers a substantial portion of southwestern Richardson. Maxwell is centered at 29.9 degrees north latitude, 98.53 degrees east longitude. It obtains northernmost and southernmost latitudes at 31.71 degrees north and 28.1 degrees north, respectively. Maxwell registers easternmost and westernmost longitudes at 100.6 degrees east and 96.45 degrees east, respectively. Maxwell Crater’s diameter measures 109.24 kilometers.

Lomonosov Crater occupies southern Maxwell Crater. The dark-floored crater marks northernmost and southernmost latitudes at 28.85 degrees north and 25.85 degrees north, respectively. Its easternmost and westernmost longitudes occur at 99.96 degrees east and 96.59 degrees east, respectively. Lomonosov has a diameter of 90.69 kilometers.

In addition to sharing space with primary craters Maxwell and Lomonosov, Richardson Crater parents satellite Richardson W on its northwestern rim. Primary crater Richardson is credited with a second satellite. Richardson E neighbors near its parent’s eastern rim.

The Richardson Crater system honors British physicist Sir Owen Willans Richardson (April 26, 1879-Feb. 15, 1959). The International Astronomical Union approved the primary crater’s official name in 1979 during the organization’s XVIIth (17th) General Assembly, held Tuesday, Aug. 14, to Thursday, Aug. 23, in Montreal, Canada. Prior to its formal naming, Richardson Crater was designated as Crater 114. The system’s two satellites received their official designations in 2006.

Sir Owen Willans Richardson was awarded the Nobel Prize in Physics 1928 in recognition of “his work on the thermionic phenomenon and especially for the discovery of the law named after him,” states the Nobel Foundation’s Nobel Prize website. Richardson’s research explains the thermionic phenomenon as a heat-generated liberation of electrons in hot metal from their atoms that allows the freed electrons to act as free charged particles.

The mathematical equation that Richardson subsequently formulated relates electron emissions with temperature. He revealed his discovery in a paper entitled “On the Negative Radiation From Hot Platinum” that he read Nov. 25, 1901, for the Cambridge Philosophical Society. He stated the equation as: “If then the negative radiation is due to the corpuscles coming out of the metal, the saturation current(s) should obey the law s = A’Θ^1/2e^-b/Θ” (page 287).

Richardson’s thermionic emission equation is known as Richardson’s law. The formula is known alternatively as the Richardson-Dushman equation in recognition of contributions by Russian-American physical chemist Saul Dushman (July 12, 1883-July 7, 1954).

The takeaways for the lunar far side’s Richardson Crater, which honors British physicist Sir Owen Willans Richardson, are that the large lunar impact participates in a chain of superimposed craters with Lomonosov and Maxwell; that Richardson occupies the northwestern quadrant, to the northeast of lunar limb straddler Mare Marginis; and that the crater’s namesake received the 1928 Nobel Prize in Physics for his research on thermionic emission, the process of electron liberation via high temperature heating.

Acknowledgment

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

Image credits:

Northward view, obtained April 1972 with 70mm Hasselblad camera during TransEarth Coast (TEC) by Apollo 16 mission, shows succession of overlapped craters (left to right; upper left), Lomonosov, Maxwell and Richardson, with Richardson E (center right) and Richardson W (upper right); camera altitude 123 kilometers; NASA ID AS16-122-19575: No known copyright restrictions, via GetArchive NARA (U.S. National Archives and Records Administration) & DVIDS (Defense Visual Information Distribution Service) Public Domain Archive @ https://nara.getarchive.net/media/as16-122-19575-apollo-16-apollo-16-mission-image-post-tei-view-northwestward-f87b9b;
Public Domain, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:AS16-122-19575.jpg

For further information:

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

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

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

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

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

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

The Moon Wiki. “Mare Marginis.” The Moon > Lunar Features Alphabetically > S Nomenclature.
Available @ https://the-moon.us/wiki/Mare_Marginis

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

Richardson, O.W. (Owen Willans). “On the Negative Radiation From Hot Platinum. Read 25 November 1901.” Mathematical Proceedings of the Cambridge Philosophical Society, vol. XI (October 29, 1900-May 19, 1902), part IV (Michaelmas Term 1901): 286-295. Cambridge UK: Cambridge University Press, 1902.
Available via Biodiversity Heritage Library @ https://biodiversitylibrary.org/page/34812898

Wayman, P. (Patrick), ed. XVIIth General Assembly Transactions of the IAU Vol. XVII B Proceedings of the 17th General Assembly Montreal, Canada, August 14-23, 1979. Washington DC: Association of Universities for Research in Astronomy, Jan. 1, 1980.
Available via IAU @ https://www.iau.org/publications/iau/transactions_b/

Wilson, William. “Owen Willans Richardson 1879-1959.” Biographical Memoirs of the Fellows of the Royal Society, vol. 5 (February 1960): 207-210.
Available via JSTOR @ https://www.jstor.org/stable/769287

Wednesday, April 4, 2012

Menzel Crater Honors American Theoretical Astrophysicist Donald Menzel

Summary: Menzel Crater honors American theoretical astrophysicist Donald Menzel, total solar eclipse observer and Harvard College Observatory’s sixth director.

Detail of Lunar Astronautical Chart (LAC) 61 shows Menzel Crater (center left) as a near side crater, with nearest named neighbor Maskelyne F, in southeastern Mare Tranquillitatis; 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

Menzel Crater honors American theoretical astrophysicist Donald Menzel, who served as Harvard College Observatory’s (HCO) sixth director and, over 55 years, between 1918 and 1973, observed 15 total solar eclipses.

Menzel Crater is a lunar impact crater in the near side’s northeastern quadrant. The tiny crater is circular and cup-shaped.

Menzel Crater is centered at 3.41 degrees north latitude, 36.94 degrees east longitude, according to the International Astronomical Union’s (IAU) Gazetteer of Planetary Nomenclature. The northern hemisphere crater obtains northernmost and southernmost latitudes of 3.46 degrees north and 3.35 degrees north, respectively. Its easternmost and westernmost longitudes occur at 37 degrees east and 36.89 degrees east, respectively. Menzel Crater’s diameter measures 3.44 kilometers.

Menzel lies in southeastern Mare Tranquillitatis (Sea of Tranquility). The lunar mare is famously associated with the first crewed lunar landing, achieved by the National Aeronautics and Space Administration’s (NASA) Apollo 11 spaceflight on Sunday, July 20, 1969.

Mare Tranquillitatis is centered at 8.35 degrees north latitude, 30.83 degrees east longitude. It records northernmost and southernmost latitudes of 19.37 degrees north and minus 4.05 degrees south, respectively. The Sea of Tranquility registers easternmost and westernmost longitudes of 45.49 degrees east and 16.92 degrees east, respectively. Mare Tranquillitatis has a diameter of 875.75 kilometers.

Maskelyne F is Menzel Crater’s nearest named neighbor. Maskelyne F lies to the northwest of Menzel Crater.

Maskelyne F numbers among the 16 satellites in the Maskelyne Crater system. The system’s primary crater, Maskelyne, logs a center-to-center distance of 210 kilometers from Apollo 11’s Mare Tranquillitatis landing site, according to the Lunar and Planetary Institute’s webpage on the Apollo 11 Mission’s landing site.

Maskelyne F is centered at 4.18 degrees north latitude, 35.3 degrees east longitude. The satellite posts northernmost and southernmost latitudes of 4.52 degrees north and 3.83 degrees north, respectively. It marks easternmost and westernmost longitudes at 35.64 degrees east and 34.95 degrees east, respectively. Maskelyne F’s diameter spans 20.93 kilometers.

Menzel Crater honors American theoretical astrophysicist Donald Howard Menzel (April 11, 1901-Dec. 14, 1976). The International Astronomical Union (IAU) approved Menzel as the tiny crater’s official name in 1979, during the organization’s XVIIth (17th) General Assembly, held from Tuesday, Aug. 14, to Thursday, Aug. 23, in Montreal, Canada.

Menzel received his Ph.D. in astrophysics from Princeton University in 1924. His advisor, Henry Norris Russell (Oct. 25, 1877-Feb. 18, 1957), was the first practitioner of the new field of astrophysics in the United States, according to American astronomers Leopold “Leo” Goldberg (Jan. 26, 1913-Nov. 1, 1987) and Lawrence Hugh Aller (Sept. 24, 1913-March 16, 2003) in the National Academy of Sciences’ Biographical Memoir, published in 1991. Menzel’s dissertation, “A Study of Line Intensities in Stellar Spectra,” considered a temperature scale for stellar spectra.

In 1952, Menzel was appointed as acting director of Harvard College Observatory (HCO). In January 1954, he became the observatory’s sixth director, a position that he held until 1966. In 1955, Menzel shepherded a beneficial association with the Smithsonian Institution. The transfer of the Smithsonian Astrophysical Observatory (SAO) from Washington DC to Cambridge in 1955 culminated in the establishment of the Harvard-Smithsonian Center for Astrophysics (CfA) in 1973.

Menzel’s interest in solar eclipses traced to his viewing of the total solar eclipse of June 8, 1918, as a Boy Scout over Evergreen, Colorado. Over the next 55 years, he enthusiastically added 14 more total solar eclipses to his solar eclipse portfolio. He traveled to western Mauritania to view the eclipse of June 30, 1973, as his last total solar eclipse.

Menzel’s retirement home in Costa Rica eased his observation of the annular eclipse of Dec. 24, 1973, as his last solar eclipse. Costa Rica qualified as one of the eclipse’s visibility regions.

In addition to his sophisticated astrophysics writings, Menzel published A Field Guide to the Stars and Planets, Including the Moon, Satellites, Comets, and Other Features of the Universe as a popular astronomy best-seller in 1964. The guide helpfully grouped the 88 modern constellations recognized by the International Astronomical Union into eight families as a memory aide for their locations.

The takeaways for Menzel Crater, which honors American theoretical astrophysicist Donald Howard Menzel, are that the tiny crater lies in southeastern Mare Tranquillitatis (Sea of Tranquility) in the near side’s northeastern quadrant; that Menzel is circular and cup-shaped; and that Menzel Crater’s namesake studied at Princeton University with Henry Norris Russell, who pioneered astrophysics in the United States; that Donald Menzel pursued his interest in solar eclipses by observing 15 total solar eclipses over 55 years; and that his publishing output includes a popular astronomy best-seller, A Field Guide to the Stars and Planets (1964), which helpfully groups the modern 88 constellations into eight families.

Detail of Shaded Relief and Color-Coded Topography Map shows Menzel Crater (center), northeast of Apollo 11 landing site (center left), in southeastern Mare Tranquillitatis, in the lunar near side’s northeastern 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:

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

DeVorkin, David. “Menzel at Princeton.” .” Journal for the History of Astronomy, vol. XXXIII, part 2, no. 111 (May 2002): 119-131.
Available via Harvard ADSABS (NASA Astrophysics Data System Abstracts) @ http://articles.adsabs.harvard.edu/full/seri/JHA../0033//0000119.000.html

Epps, Garrett. “Menzel’s Martians Frolic.” The Harvard Crmson. Dec. 16, 1970.
Available @ https://www.thecrimson.com/article/1970/12/16/menzels-martians-frolic-pthe-martians-in/

Goldberg, Leo; and Lawrence H. Aller. “Donald Howard Menzel 1901-1976.” National Academy of Sciences Biographical Memoir. Washington DC: National Academy of Sciences, 1991.
Available via NAS (National Academy of Sciences) Online @ http://www.nasonline.org/publications/biographical-memoirs/memoir-pdfs/menzel-donald-1.pdf

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

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “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. “Maskelyne F.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > The Moon. Last updated Oct. 18, 2010.
Available @ https://planetarynames.wr.usgs.gov/Feature/11206

International Astronomical Union (IAU) / U.S. Geological Survey (USGS) Gazetteer of Planetary Nomenclature. “Menzel.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature > Nomenclature > The Moon. Last updated Oct. 18, 2010.
Available @ https://planetarynames.wr.usgs.gov/Feature/3846

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

Lunar and Planetary Institute. “Landing Site Overview.” Lunar and Planetary Institute > Lunar Science and Exploration Portal > Exploration > Lunar Mission Studies > Lunar Exploration Timeline: 1969: Apollo 11.
Available @ https://www.lpi.usra.edu/lunar/missions/apollo/apollo_11/landing_site/

Marriner, Derdriu. “Jettisoned LM Snoopy Descent Stage Appeared Near Taruntius Crater.” Earth and Space News. Wednesday, May 11, 2011.
Available @ https://earth-and-space-news.blogspot.com/2011/05/jettisoned-lm-snoopy-descent-stage.html

Marriner, Derdriu. “Lunar Near Side’s Taruntius Crater System Lost Four Satellites in 1976.” Earth and Space News. Wednesday, April 27, 2011.
Available @ https://earth-and-space-news.blogspot.com/2011/04/lunar-near-sides-taruntius-crater.html

Marriner, Derdriu. “Lunar Taruntius Crater System Borders Northwestern Mare Fecunditatis.” Earth and Space News. Wednesday, April 13, 2011.
Available @ https://earth-and-space-news.blogspot.com/2011/04/lunar-taruntius-crater-system-borders.html

Marriner, Derdriu. “Lunar Taruntius Crater System Lost Three Satellites in 1973.” Earth and Space News. Wednesday, April 20, 2011.
Available @ https://earth-and-space-news.blogspot.com/2011/04/lunar-taruntius-crater-system-lost.html

Marriner, Derdriu. “Taruntius Crater Parents 15 Satellites on Northwest Mare Fecunditatis.” Earth and Space News. Wednesday, May 4, 2011.
Available @ https://earth-and-space-news.blogspot.com/2011/05/taruntius-crater-parents-15-satellites.htmla

Menzel, Donald H. “Doodling as a Form of Art.” Leonardo, vol. 1, no. 2 (April 1968): 175-177. Available @ https://muse.jhu.edu/article/596558/pdf

Menzel, Donald H. “IV. Order and System of the Constellations.” A Field Guide to the Stars and Planets, Including the Moon, Satellites, Comets, and Other Features of the Universe. First edition. Boston MA: Houghton Mifflin Company, 1964.
Available via HathiTrust @ https://catalog.hathitrust.org/Record/001476091
Available via Internet Archive @ https://archive.org/details/AFieldguideToTheStarsAndPlanets-DonaldMenzel/

Menzel, Donald H. “A Study of Line Intensities in Stellar Spectra.” Harvard College Observatory Circular, vol. 258: 1-20.
Available via Harvard ADSABS (NASA Astrophysics Data System Abstracts) @ http://adsabs.harvard.edu/full/1924HarCi.258....1M
Available via Harvard ADSABS (NASA Astrophysics Data System Abstracts) @ http://adsabs.harvard.edu/pdf/1924HarCi.258....1M

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

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

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

Osterbrock, Donald E. “Young Don Menzel’s Amazing Adventures at Lick Observatory.” Journal for the History of Astronomy, vol. XXXIII, part 2, no. 111 (May 2002): 95-118.
Available via Harvard ADSABS (NASA Astrophysics Data System Abstracts) @ http://adsabs.harvard.edu/full/2002JHA....33...95O
Available via Harvard ADSABS (NASA Astrophysics Data System Abstracts) @ http://adsabs.harvard.edu/pdf/2002JHA....33...95O

Pasachoff, Jay M. “Menzel and Eclipses.” Journal for the History of Astronomy, vol. XXXIII, part 2, no. 111 (May 2002): 139-156.
Available via Harvard ADSABS (NASA Astrophysics Data System Abstracts) @ http://articles.adsabs.harvard.edu/full/seri/JHA../0033//0000139.000.html