First of Four 2011 Partial Solar Eclipses Happens Tuesday, Jan. 4

Summary: The first of four 2011 partial solar eclipses happens Tuesday, Jan. 4, with North Africa, western and central Asia, and Europe favored for visibility.

Earth visibility chart and eclipse statistics for partial solar eclipse of Jan. 4, 2011: "Permission is freely granted to reproduce this data when accompanied by an acknowledgment, Eclipse Predictions by Fred Espenak, NASA GSFC Emeritus," via NASA Eclipse Web Site

The first of four 2011 partial solar eclipses happens Tuesday, Jan. 4, with the path of visibility favoring North Africa, western and central Asia, and Europe.

The moon’s passage between Earth and the solar system’s sun occasions a solar eclipse. A partial solar eclipse occurs as a partial obscuring of the solar image for observers on Earth. The first of four 2011 partial solar eclipses begins with first contact of the moon’s penumbral shadow with Earth’s surface. First contact takes place Tuesday, Jan. 4, at 6:40:11 Universal Time (7:40:11 a.m. Central European Time in Rome, Italy; 1:40:11 a.m. Eastern Standard Time). P1 is the designator for first contact with the shadow’s light, outer region, known as penumbra.

The NASA Eclipse Web Site identifies northern Algeria as the location on the Earth’s surface where the moon’s penumbral shadow makes first contact.

In Rome, Italy, where sunrise takes place at 7:37 a.m. CET (6:37 UT; 1:37 a.m. EST), the sun is close to the horizon. Time And Date web site recommends that observers have free sight to the east-southeast.

Greatest eclipse takes place Tuesday, Jan. 4, at 8:50:35 UT (9:50:35 a.m. CET in Rome, Italy; 3:50:35 a.m. EST). Greatest eclipse pertains to the instant of closest passage of the axis of the lunar shadow cone to Earth’s center.

On the NASA Eclipse Web Site, retired astrophysicist Fred Espenak, known as “Mr. Eclipse,” indicates that greatest eclipse occurs in northern Sweden. At the instant of greatest eclipse, the axis of the lunar shadow passes only 510 kilometers (316.89 miles) above Earth’s surface.

The penumbra’s last contact with Earth’s surface registers the eclipse’s end. Exit from the lunar penumbra occurs Tuesday, Jan. 4, at 11:00:54 UT (12:00:54 p.m. CET in Rome, Italy; 6:00:54 a.m. EST). P4 is the designator for last contact with the penumbra.

The January 2011 partial solar eclipse belongs to Saros 151. The Saros cycle recognizes families, known as series, for lunar and solar eclipses. A Saros cycle has a periodicity of approximately 6,585.3 days (18 years 11 days 8 hours).

The four 2011 partial solar eclipses belong to the 21st century’s most common eclipse type. Of the century’s 224 solar eclipses, 77 are partial.

Annular eclipses rate as the century’s second most common solar eclipse. Annular eclipses account for 72 of the century’s 224 solar eclipses.

Total solar eclipses comprise the century’s third most common type of solar eclipse. Total solar eclipses contribute 68 occurrences to the century’s solar eclipse total.

Hybrid solar eclipses make the least frequent appearances of the four solar eclipse types. Hybrid solar eclipses occur only seven times in the 21st century.

The four 2011 partial solar eclipses qualify the year for elite rating as only one of six years in the 21st century featuring four solar eclipses. The century mostly experiences the annual minimum of solar eclipses, with 82 years having only two solar eclipses. Three solar eclipses per year occur in 12 years. The maximum of five solar eclipses in a calendar year does not happen in the 21st century.

The four 2011 solar eclipses share the year’s eclipse lineup with two lunar eclipses. The NASA Eclipse Web Site notes the rarity of the year’s 4:2 combination of lunar and solar eclipses. The 4:2 combination happens in only six years during the 21st century: 2011, 2029, 2047, 2065, 2076 and 2094.

Occurrences in January and December frame the century’s 4:2 eclipse combination. The Tuesday, Jan. 4, partial solar eclipse initiates the 4:2 lineup for 2011. A total lunar eclipse on Saturday, Dec. 10, closes 2011’s 4:2 lineup.

Observers along the path of visibility should remember that partial solar eclipses should not be viewed directly. Safe viewing of partial solar eclipses requires proper equipment and techniques.

The takeaway for the first of four 2011 partial solar eclipses, which takes place Tuesday, Jan. 4, is the event’s favoring of northern Africa, west and central Asia, and Europe for visibility.

animation of Jan. 4, 2011, solar eclipse: A.T. Sinclair/NASA Goddard Space Flight Center (GSFC), Public Domain, via Wikimedia Commons

Acknowledgment

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

Image credits:

Earth visibility chart and eclipse statistics for partial solar eclipse of Jan. 4, 2011: "Permission is freely granted to reproduce this data when accompanied by an acknowledgment, Eclipse Predictions by Fred Espenak, NASA GSFC Emeritus," via NASA Eclipse Web Site @ https://eclipse.gsfc.nasa.gov/OH/OHfigures/OH2011-Fig01.pdf

animation of Jan. 4, 2011, solar eclipse: A.T. Sinclair/NASA Goddard Space Flight Center (GSFC), Public Domain, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:SE2011Jan04P.gif

For further information:

“January 4, 2011 -- Partial Solar Eclipse.” TimeAndDate > Sun & Moon > Eclipses.
Available @ https://www.timeanddate.com/eclipse/solar/2011-january-4

“January 4, 2011 -- Partial Solar Eclipse -- Rome.” TimeAndDate > Sun & Moon > Eclipses.
Available @ https://www.timeanddate.com/eclipse/in/italy/rome?iso=20110104

Espenak, Fred. “Eclipses During 2011.” NASA Eclipse Web Site > Observer’s Handbook.
Available via NASA Eclipse Web Site@ https://eclipse.gsfc.nasa.gov/OH/OH2011.html

Espenak, Fred. “Five Millennium Catalog of Solar Eclipses: 2001 to 2100 (2001 CE to 2100 CE).” NASA Eclipse Web Site > Solar Eclipses.
Available via NASA Eclipse Web Site @ https://eclipse.gsfc.nasa.gov/SEcat5/SE2001-2100.html

Espenak, Fred. “Greatest Eclipse.” NASA Eclipse Web Site > Glossary of Solar Eclipse Terms.
Available via NASA Eclipse Web Site @ https://eclipse.gsfc.nasa.gov/SEhelp/SEglossary.html

Espenak, Fred. "Partial Solar Eclipse of 2011 Jan 04." NASA Eclipse Web Site > Solar Eclipses Past and Future: Eclipses During: 2011 > Eclipses During 2011: 2011 Jan 04: Partial Solar Eclipse.
Available via NASA Eclipse Web Site @ https://eclipse.gsfc.nasa.gov/OH/OHfigures/OH2011-Fig01.pdf

Espenak, Fred. “Table 1 -- Local Circumstances for Partial Solar Eclipse of 2011 Jan 04.” NASA Eclipse Web Site > Observer’s Handbook > Observer’s Handbook Tables.
Available via NASA Eclipse Web Site @ https://eclipse.gsfc.nasa.gov/OH/OHtables/OH2011-Tab01.pdf

Littmann, Mark; Ken Willcox; Fred Espenak. “Observing Solar Eclipses Safely.” MrEclipse > Totality.
Available @ http://www.mreclipse.com/Totality2/TotalityCh11.html

Marriner, Derdriu. "Jan. 4, 2011, Partial Solar Eclipse Belongs to Saros Series 151." Earth and Space News. Wednesday, Dec. 22, 2010.
Available @ https://earth-and-space-news.blogspot.com/2010/12/jan-4-2011-partial-solar-eclipse.html

Jan. 4, 2011, Partial Solar Eclipse Belongs to Saros Series 151

Summary: The Tuesday, Jan. 4, 2011, partial solar eclipse belongs to Saros cycle 151, a series of 72 similar lunar eclipses.

Partial solar eclipse of Aug. 14, 1776, opened Saros solar series 151’s lineup of 72 solar eclipses: "Permission is freely granted to reproduce this data when accompanied by an acknowledgment, Eclipse Predictions by Fred Espenak and Jean Meeus (NASA's GSFC)," via NASA Eclipse Web Site

The Tuesday, Jan. 4, 2011, partial solar eclipse belongs to Saros cycle 151, which comprises 72 lunar eclipses with similar geometries.

Early January’s partial solar eclipse begins Tuesday, Jan. 4, 2011, at 06:40:11 Universal Time, according to the NASA Eclipse Web Site. The instant of the closest passage of the lunar shadow cone’s axis to Earth’s center, known as the greatest eclipse, occurs Tuesday, Jan. 4, at 08:50:35 UT. The eclipse ends Tuesday, Jan. 4, at 11:00:54 UT.

January 2011’s partial solar eclipse appears as number 14 in the lineup of 72 solar eclipses that compose Saros cycle 125. Similar geometries unite the 72 solar eclipses into a family, known as a series.

The NASA Eclipse Web Site describes Saros 151 solar eclipses as sharing the geometry of occurring at the moon’s ascending node. With each succeeding eclipse in Saros 151, the lunar movement is southward with respect to the ascending node.

A pair of ascending and descending nodes mark the intersections of Earth’s orbit by the moon’s orbit. The two nodes reveal the approximately 5.1 degree tilt of the moon’s orbit with respect to Earth’s orbit. The ascending node represents the lunar orbital crossing to the north of Earth’s orbit. The descending node associates with the lunar orbital crossing to the south of Earth’s orbit.

The Saros cycle of approximately 6,585.3 days (18 years 11 days 8 hours) governs the periodicity and recurrence of solar eclipses. Each Saros series comprises 70 or more eclipses that typically span 12 to 13 centuries.

Saros solar series 151 endures for 1,280.14 years, according to the NASA Eclipse Web Site. The series spans 14 centuries. Saros solar series 151 stretches from the 18th through the 31st centuries.

Solar eclipses in Saros series 151 occur in the sequence order of 18 partial solar eclipses, six annular solar eclipses, one hybrid solar eclipse, 39 total solar eclipses and eight partial solar eclipses. Total solar eclipses account for the most number of Saros series 151 eclipses, with a total of 39 occurrences. Partial solar eclipses rate as the second most frequent solar eclipse type in the series, with a total of 26 occurrences.

The 18th century’s partial solar eclipse of Wednesday, Aug. 14, 1776, opened Saros solar series 151. This Northern Hemisphere event experienced its greatest eclipse, with coordinates of 70.6 north at 123.5 west, over Amundsen Gulf, between Banks Island and the mainland, Inuvik Region, Northwest Territories, in the Canadian Arctic Archipelago.

The 31st century’s partial solar eclipse of Wednesday, Oct. 1, 3056, ends Saros solar series 151. This Southern Hemisphere event's greatest eclipse will occur, with coordinates of 72.1 south at 106.6 west, over the Southern Ocean, northwest of West Antarctica's Thurston Island.

January 2011’s partial solar eclipse occurs as number 14 within the opening sequence of 18 partial solar eclipses in Saros series 151. This Northern Hemisphere event's greatest eclipse, with coordinates of 64.7 north at 20.8 east, takes place over northeastern Västerbotten County in northeastern Sweden.

January 2011’s partial solar eclipse practically coincides with Earth’s perihelion (Ancient Greek περί, perí, “near” + ἥλιος, hḗlios, “sun”). The year’s closest center-to-center orbital point of Earth with the sun takes place Tuesday, Jan. 4, at 08:52 Greenwich Mean Time (GMT), two minutes after the instant of greatest eclipse. Perihelion will measure 0.9832860 astrononomical units (AU), according to retired NASA astrophysicist Fred Espenak's AstroPixels website. The year's perihelion equates to approximately 147,105,755 kilometers (perihelion's mean value of 0.9832899 AU, 147,098,074 kilometers, plus 2011 perihelion's relative distance of 7,681 kilometers with respect to the mean value).

The partial solar eclipse of Thursday, Dec. 24, 1992, was the immediate predecessor of January 2011’s partial solar eclipse in Saros series 151. This Northern Hemisphere event staged its greatest eclipse, with coordinates of 65.7 north at 155.7 east, over northeastern Republic of Sakha in the Russian Far East Federal District.

The successor of January 2011’s partial solar eclipse in Saros series 151 will appear Sunday, Jan. 14, 2029. This Northern Hemisphere event's greatest eclipse, with coordinates of 63.7 north at 114.2 west, will take place over Canada's North Slave Region in the Northwest Territories, north of Yellowknife and south of Wekweètì.

The takeaway for the Jan. 4, 2011, partial solar eclipse is that the event occurs as number 14 in Saros solar series 151’s lineup of 72 solar eclipses.

Partial solar eclipse of Jan. 14, 2029, succeeds January 2011’s partial solar eclipse in the Saros 151 solar series: "Permission is freely granted to reproduce this data when accompanied by an acknowledgment, Eclipse Predictions by Fred Espenak and Jean Meeus (NASA's GSFC)," via NASA Eclipse Web Site

Acknowledgment

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

Image credits:

Partial solar eclipse of Aug. 14, 1776, opened Saros solar series 151’s lineup of 72 solar eclipses: "Permission is freely granted to reproduce this data when accompanied by an acknowledgment, Eclipse Predictions by Fred Espenak and Jean Meeus (NASA's GSFC)," via NASA Eclipse Web Site @ https://eclipse.gsfc.nasa.gov/5MCSEmap/1701-1800/1776-08-14.gif

Partial solar eclipse of Jan. 14, 2029, succeeds January 2011’s partial solar eclipse in the Saros 151 solar series: "Permission is freely granted to reproduce this data when accompanied by an acknowledgment, Eclipse Predictions by Fred Espenak and Jean Meeus (NASA's GSFC)," via NASA Eclipse Web Site @ https://eclipse.gsfc.nasa.gov/5MCSEmap/2001-2100/2029-01-14.gif

For further information:

Espenak, Fred “Delta T (ΔT) and Universal Time.” NASA Eclipse Web Site > Eclipse Resources > Special Help Features.
Available via NASA Eclipse Web Site @ https://eclipse.gsfc.nasa.gov/SEhelp/deltaT.html

Espenak, Fred. “Earth at Perihelion and Aphelion: 2001 to 2100.” AstroPixels > Ephemeris > Earth > Perihelion and Aphelion: 2001 to 2100 (GMT).
Available via AstroPixels @ http://www.astropixels.com/ephemeris/perap2001.html

Espenak, Fred. “Eclipses and the Saros.” NASA Eclipse Web Site > Solar Eclipses > Solar Eclipse Catalogs >: Saros Catalog of Solar Eclipses: Saros 0-180.
Available via NASA Eclipse Web Site @ https://eclipse.gsfc.nasa.gov/SEsaros/SEsaros.html

Espenak, Fred. “Partial 1776 Aug 14.” NASA Eclipse Web Site > Solar Eclipses > Solar Eclipse Catalogs >: Saros Catalog of Solar Eclipses: Saros 0-180 > Eclipses and the Saros: Return to Catalog of Solar Eclipse Saros Series > Solar Eclipses of Saros 0 to 180: Summary of Saros Series 150 to 175: 151 > Saros Series 151: Catalog of Solar Eclipses of Saros 151: 08981 -34 1776 Aug 14.
Available via NASA Eclipse Web Site @ https://eclipse.gsfc.nasa.gov/5MCSEmap/1701-1800/1776-08-14.gif

Espenak, Fred. “Partial 1992 Dec 24.” NASA Eclipse Web Site > Solar Eclipses > Solar Eclipse Catalogs >: Saros Catalog of Solar Eclipses: Saros 0-180 > Eclipses and the Saros: Return to Catalog of Solar Eclipse Saros Series > Solar Eclipses of Saros 0 to 180: Summary of Saros Series 150 to 175: 151 > Saros Series 151: Catalog of Solar Eclipses of Saros 151: 09492 -22 1992 Dec 24.
Available via NASA Eclipse Web Site @ https://eclipse.gsfc.nasa.gov/5MCSEmap/1901-2000/1992-12-24.gif

Espenak, Fred. "Partial 2011 Jan 04.” NASA Eclipse Web Site > Solar Eclipses > Solar Eclipse Catalogs >: Saros Catalog of Solar Eclipses: Saros 0-180 > Eclipses and the Saros: Return to Catalog of Solar Eclipse Saros Series > Solar Eclipses of Saros 0 to 180: Summary of Saros Series 150 to 175: 151 > Saros Series 151: Catalog of Solar Eclipses of Saros 151: 09531 -21 2011 Jan 04.
Available via NASA Eclipse Web Site @ https://eclipse.gsfc.nasa.gov/5MCSEmap/2001-2100/2011-01-04.gif

Espenak, Fred. "Partial 2029 Jan 14.” NASA Eclipse Web Site > Solar Eclipses > Solar Eclipse Catalogs >: Saros Catalog of Solar Eclipses: Saros 0-180 > Eclipses and the Saros: Return to Catalog of Solar Eclipse Saros Series > Solar Eclipses of Saros 0 to 180: Summary of Saros Series 150 to 175: 151 > Saros Series 151: Catalog of Solar Eclipses of Saros 151: 09571 -20 2029 Jan 14.
Available via NASA Eclipse Web Site @ https://eclipse.gsfc.nasa.gov/5MCSEmap/2001-2100/2029-01-14.gif

Espenak, Fred. "Partial Solar Eclipse of 1776 Aug 14.” EclipseWise > Solar Eclipses > Solar Eclipse Links > Six Six Millennium Catalog of Solar Eclipses -2999 to 3000 (3000 BCE to 3000 CE) > 1701 to 1800 (1701 CE to 1800 CE).
Available via EclipseWise @ http://eclipsewise.com/solar/SEprime/1701-1800/SE1776Aug14Pprime.html

Espenak, Fred. “Partial Solar Eclipse of 1992 Dec 24.” EclipseWise > Solar Eclipses > Solar Eclipse Links > Six Millennium Catalog of Solar Eclipses > -2999 to 3000 (3000 BCE to 3000 CE) > 1901 to 2000 (1901 CE to 2000 CE).
Available via EclipseWise @ http://eclipsewise.com/solar/SEprime/1901-2000/SE1992Dec24Pprime.html

Espenak, Fred. "Partial Solar Eclipse of 2011 Jan 04.” EclipseWise > Solar Eclipses > Solar Eclipse Links > Six Six Millennium Catalog of Solar Eclipses -2999 to 3000 (3000 BCE to 3000 CE) > 2001 to 2100 (2001 CE to 2100 CE).
Available via EclipseWise @ http://eclipsewise.com/solar/SEprime/2001-2100/SE2011Jan04Pprime.html

Espenak, Fred. "Partial Solar Eclipse of 2029 Jan 14.” EclipseWise > Solar Eclipses > Solar Eclipse Links > Six Six Millennium Catalog of Solar Eclipses -2999 to 3000 (3000 BCE to 3000 CE) > 2001 to 2100 (2001 CE to 2100 CE).
Available via EclipseWise @ http://eclipsewise.com/solar/SEprime/2001-2100/SE2029Jan14Pprime.html

Espenak, Fred. “Partial Solar Eclipse of January 04.” NASA Eclipse Web Site > Solar Eclipses > Solar Eclipses: Past and Future.
Available via NASA Eclipse Web Site @ https://eclipse.gsfc.nasa.gov/OH/OH2011.html

Espenak, Fred. “Saros Series 151.” NASA Eclipse Web Site > Solar Eclipses > Solar Eclipse Catalogs > Saros Catalog of Solar Eclipses: Saros 0-180.
Available via NASA Eclipse Web Site @ https://eclipse.gsfc.nasa.gov/SEsaros/SEsaros151.html

Marriner, Derdriu. “Dec. 21, 2010, Total Lunar Eclipse Belongs to Saros Cycle 125.” Earth and Space News. Wednesday, Dec. 8, 2010.
Available @ https://earth-and-space-news.blogspot.com/2010/12/dec-21-2010-total-lunar-eclipse-belongs.html

Smith, Ian Cameron. “Partial Solar Eclipse of 4 Jan, 2011 AD.” Moon Blink > Hermit Eclipse > Eclipse Database > Full Solar Catalog > 2001-3000 AD > 2001-2020 AD.
Available @ https://moonblink.info/Eclipse/eclipse/2011_01_04

Smith, Ian Cameron. “Partial Solar Eclipse of 14 Jan, 2029 AD.” Moon Blink > Hermit Eclipse > Eclipse Database > Full Solar Catalog > 2001-3000 AD > 2021-2040 AD.
Available @ https://moonblink.info/Eclipse/eclipse/2029_01_14

Smith, Ian Cameron. “Partial Solar Eclipse of 14 Aug, 1776 AD.” Moon Blink > Hermit Eclipse > Eclipse Database > Full Solar Catalog > 1001-2000 AD > 1701 AD > 1761-1780 AD.
Available @ https://moonblink.info/Eclipse/eclipse/1776_08_14

Smith, Ian Cameron. “Partial Solar Eclipse of 24 Dec, 1992 AD.” Moon Blink > Hermit Eclipse > Eclipse Database > Full Solar Catalog > 1001-2000 AD > 1901 AD > 1981-2000 AD.
Available @ https://moonblink.info/Eclipse/eclipse/1992_12_24

2010 Total Lunar Eclipse Tuesday, Dec. 21, Favors North America

Summary: As the year’s second eclipse of the moon, the 2010 total lunar eclipse Tuesday, Dec. 21, favors North America.

visibility of the Dec. 21, 2010, lunar eclipse: Fred Espenak/NASA Goddard Space Flight Center (GSFC), Public Domain, via Wikimedia Commons

As the year’s second eclipse of the moon, the 2010 total lunar eclipse Tuesday, Dec. 21, favors North America, northwestern South America (Colombia, Ecuador, Peru, Venezuela), Greenland, Iceland, northern Scandinavia and northern Russia with entire visibility.

NASA’s Eclipse Web Site details the astronomical event as beginning at 5:29:17 Universal Time (12:29 a.m. Eastern Standard Time) with a penumbral eclipse, with the lunar passage through the penumbra, the faint, outer cone of Earth’s shadow. Astronomers designate the penumbral start as P1.

At 6:32:37 UT (1:32 a.m. EST), the event’s partial eclipse begins. Partiality signals the movement of only a portion of the visible lunar surface into the umbra, the darkest, innermost segment of Earth’s shadow. U1 designates the start of partiality.

At 7:40:47 UT (2:40 a.m. EST), the total eclipse begins. Totality indicates the moon’s complete movement into Earth’s umbra. U2 is the astronomical designation for the start of totality.

Greatest eclipse takes place at 8:16:57 UT (3:16 a.m. EST). Greatest eclipse references the instant of the moon's closest passage to the axis of Earth's shadow.

The total eclipse ends at 8:53:08 UT (3:53 a.m. EST). U3 designates the end of totality.

The partial eclipse ends at 10:01:20 UT (5:01 a.m. EST). U4 designates the end of partiality.

At 11:04:31 UT (6:04 a.m. EST) the penumbral eclipse ends. P4 designates the penumbral end.

The penumbral eclipse frames the December 2010 lunar event. The penumbral eclipse, occurring from 5:29:17 UT (12:29 a.m. EST) to 11:04 UT (6:04:31 a.m. EST), accounts for 5 hours 35 minutes 14 seconds.

Like a set of Russian nesting dolls, the penumbral eclipse encompasses a partial eclipse and a total eclipse within its time span. Partiality, spanning 6:32:37 UT (1:32 a.m. EST) to 10:01:20 UT (5:01 a.m. EST), has a duration of 3 hours 28 minutes 43 seconds. Totality, which runs from 7:40 UT (2:40:47 a.m. EST) to 8:53:08 UT (3:53 a.m. EST), has a duration of 1 hour 12 minutes 21 seconds.

The 2010 total lunar eclipse ends a drought of almost 2 years 10 months of no total lunar eclipses. The most recent predecessor of the Dec. 21, 2010, total lunar eclipse took place early in 2008.

Time And Date’s web site frames the 2008 total lunar eclipse with a penumbral eclipse that started at 00:36:36 UT, Thursday, Feb. 21 (7:36 p.m. EST, Wednesday, Feb. 20) and ended Feb. 21 at 6:15:36 UT (1:15 a.m. EST). Totality occurred between 3:01:10 UT, Feb. 21 (10:01 p.m. EST, Feb. 20) and 3:50:54 UT, Feb. 21 (10:50 p.m. EST, Feb. 20).

The 2010 total lunar eclipse also shares its date with the Northern Hemisphere’s winter solstice, which is known as the summer solstice in the Southern Hemisphere. The second of the two annual solstices takes place Dec. 21, 2010, at 23:38 UT (6:38 p.m. EST). A span of about 12 hours 34 minutes separates the end of the day’s lunar eclipse and the solstice’s official start.

The 2010 total lunar eclipse Tuesday, Dec. 21, happens as the second of the year’s two lunar eclipses. The year’s first lunar eclipse occurred Saturday, June 26, as a partial lunar eclipse.

December 2010's total lunar eclipse belongs to Saros 125. The Saros cycle for lunar and solar eclipses encompasses a period of 18 years 11 days 8 hours (approximately 6,585.3 days). The Saros cycle organizes eclipses into families, known as series.

The takeaway for the 2010 total lunar eclipse Tuesday, Dec. 21, is that the event favors North America as the only continent with entire visibility, coincides with the year’s December solstice and ends a 2 year 9-plus month drought of total lunar eclipses.

moon’s approximate appearance during passage through Earth’s shadows, with red glowing light inside the umbral shadow: SockPuppetForTomruen at English Wikipedia, Public Domain, via Wikimedia Commons

Acknowledgment

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

Image credits:

visibility of the Dec. 21, 2010, lunar eclipse: Fred Espenak/NASA Goddard Space Flight Center (GSFC), Public Domain, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:Visibility_Lunar_Eclipse_2010-12-21.png

moon’s approximate appearance during passage through Earth’s shadows, with red glowing light inside the umbral shadow: SockPuppetForTomruen at English Wikipedia, Public Domain, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:Lunar_eclipse_chart_close-2010Dec21_animation.gif

For further information:

“February 20 / February 21, 2008 -- Total Lunar Eclipse.” Time And Date > Sun & Moon > Eclipses.
Available @ https://www.timeanddate.com/eclipse/lunar/2008-february-21

“December 20 / December 21, 2010 -- Total Lunar Eclipse.” Time And Date > Sun & Moon > Eclipses.
Available @ https://www.timeanddate.com/eclipse/lunar/2010-december-21

“Earth’s Seasons: Equinoxes, Solstices, Perihelion, and Aphelion.” U.S. Naval Observatory Astronomical Applications Department > Data Services.
Available @ http://aa.usno.navy.mil/data/docs/EarthSeasons.php

Espenak, Fred. “2010 Dec 21: Total Lunar Eclipse.” NASA Eclipse Web Site > Eclipses During 2010.
Available @ https://eclipse.gsfc.nasa.gov/OH/OH2010.html

Espenak, Fred; Jean Meeus. "Saros Series 125." NASA Eclipse Web Site > Lunar Eclipses > Catalog of Lunar Eclipse Saros Series.
Available @ https://eclipse.gsfc.nasa.gov/LEsaros/LEsaros125.html

Marriner, Derdriu. "Dec. 21, 2010, Total Lunar Eclipse Belongs to Saros Cycle 125." Earth and Space News. Wednesday, Dec. 8, 2010.
Available @ https://earth-and-space-news.blogspot.com/2010/12/dec-21-2010-total-lunar-eclipse-belongs.html

Marriner, Derdriu. "One Exeligmos Unites Dec. 21, 2010, and Nov. 18, 1956, Lunar Eclipses." Earth and Space News. Wednesday, Dec. 1, 2010.
Available @ https://earth-and-space-news.blogspot.com/2010/12/one-exeligmos-unites-dec-21-2010-and.html

“When Is the Longest/Shortest Day? Summer/Winter Solstices and Spring/Autumn Equinoxes.” Greenwich Mean Time.
Available @ https://greenwichmeantime.com/longest-day/equinox-solstice-2010-2019/

Tree Electrical Safety Knowledge, Precautions, Risks and Standards

Summary: Randall H. Miller weighs tree electrical safety knowledge, electrical safety precautions and electrical safety standards against electrical safety risks.

Trees and electrical lines, a common occurrence in the modern world's electrified landscape, present potential electrical safety risks; Italian Cypress (Cupressus sempervirens) and electrical power lines near Eastern and Cottage streets, Sacramento, northern Central Valley, California: Robert Couse Baker (**RCB**), CC BY 2.0 Generic, via Flickr

Tree electrical safety knowledge arises from accepting electrical safety precautions, acknowledging electrical safety risks and acting on electrical safety standards, according to Electrical Knowledge in the December 2010 issue of Arborist News.

Author Randall H. Miller begins with a description of electrical contact with high-voltage electrical lines running through trees as "the most common fatal accident involving arborists." Electricity, like water, always claims the path of least resistance to ground, where "it dissipates in concentric 'ripples'" before the "electric charges return to their source." Voltage, from 120 for households to 765,000 for the biggest transmission lines in North America, describes the electrical potential of fully energized electrical lines for work.

Amperage expresses the measured but variable flow of an electrical current that "realizes its 'potential'" by starting to work through a conductive wire in a circuit.

Downed electrical lines, electrical lines running through trees and trees atop electrical lines furnish scenarios where tree electrical safety knowledge must translate into electrical safety precautions.

Downed lines generate threats of electrical contact by arcing and whipping around into bystanders and by energizing such conductive objects as fences, metal-sided buildings and vehicles. Occupants forced to evacuate energized vehicles have to jump clear, land "feet together" and shuffle off bounding "one foot to the ground" or hopping "feet together." Climbing, picking fruits and nuts, playing in tree houses and on tree swings, or pruning is not advisable for any trees through which electrical lines run.

Running clothes lines for outdoor-dried freshness jeopardizes people in the house and on the ground if the anchoring branch or trunk fails atop an electrical line.

Tree electrical safety knowledge keeps point of contact as the most important phrase to remember when tree-loving non-specialists and specialists seek to minimize electrical safety risks. "[S]imultaneously touching an energized object and the ground, an energized object and another conductor, grounded object" leads a person to serve as electricity's path to ground. "[M]ultiple contact with a single energized object (such as two hands, a hand and foot, or any other combination of body parts)" may open similar pathways.

A person respectively needs only 16, 20 or 100 milliamps to be unsuccessful at loosening a handhold, to experience respiratory paralysis or to suffer ventricular fibrillation. Cardiac arrest and internal organ damage occur at contact with two amps even though people survive point-of-contact surface temperatures of 1862 degrees Fahrenheit (1000 degrees Celsius).

The American National Standards Institute's ANSI Z133 and the Occupational Safety and Health Administration's OSHA 1910.269 promote tree electrical safety knowledge through U.S. electrical safety standards.

Z133 quantifies as hazardous distances under 10 feet (3 meters) to energized, 50-kV overhead conductors, with 04.-inch (92-millimeter) expansions for every kilovolt increase over 50 kV. It reveals the dangers of directly contacting power lines and of indirectly contacting conductive objects touching energized fixtures such as ground, people, telecom wires and tools. It specifies step potential as electricity jumping through someone straddling higher- and lower-voltage ground ripples and touch potential as electricity in contact with multiple energized points.

Tree electrical safety knowledge turns backyards into minimal electrical safety risks from direct, indirect, step or touch contact through electrical safety precautions and electrical safety standards.

Arbor Day 2010 campaign by Public Service of New Hampshire (PSNH) to promote tree electrical safety knowledge; Thursday, May 6, 2010: PSNH, CC BY ND 2.0 Generic, via Flickr

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:

Trees and electrical lines, a common occurrence in the modern world's electrified landscape, present potential electrical safety risks; Italian Cypress (Cupressus sempervirens) and electrical power lines near Eastern and Cottage streets, Sacramento, northern Central Valley, California: Robert Couse Baker (**RCB**), CC BY 2.0 Generic, via Flickr @ https://www.flickr.com/photos/29233640@N07/2829065451/

Arbor Day 2010 campaign by Public Service of New Hampshire (PSNH) to promote tree electrical safety knowledge; Thursday, May 6, 2010: PSNH, CC BY ND 2.0 Generic, via Flickr @ https://www.flickr.com/photos/psnh/4584161944/

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.

International Society of Arboriculture. 2005. Glossary of Arboricultural Terms. Champaign IL: International Society of Arboriculture.

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

Miller, Randall H. December 2010. "Electrical Knowledge." Arborist News 19(6): 12-17.

Dec. 21, 2010, Total Lunar Eclipse Belongs to Saros Cycle 125

Summary: The Tuesday, Dec. 21, 2010, total lunar eclipse belongs to Saros cycle 125, a series of 72 similar lunar eclipses.

Penumbral lunar eclipse of July 17, 1163, opened Saros 125’s lineup of 72 lunar eclipses: "Permission is freely granted to reproduce this data when accompanied by an acknowledgment, Eclipse Predictions by Fred Espenak and Jean Meeus (NASA's GSFC)," via NASA Eclipse Web Site

The Tuesday, Dec. 21, 2010, total lunar eclipse belongs to Saros cycle 125, which comprises 72 lunar eclipses with similar geometries.

Late December’s total lunar eclipse begins Tuesday, Dec. 21, at 5:29:17 Universal Time (12:29:17 a.m. Eastern Standard Time), according to NASA’s Eclipse Web Site. The eclipse ends 11:04:31 UT (6:04:31 a.m. EST).

December 2010’s total lunar eclipse appears as number 48 in the lineup of 72 lunar eclipses that compose Saros cycle 125. Similar geometries unite the 72 lunar eclipses into a family, known as a series.

Retired NASA astrophysicist Fred Espenak’s EclipseWise website describes Saros 125 lunar eclipses as sharing the geometry of occurring at the moon’s descending node. With each succeeding eclipse in Saros 125, the lunar movement is northward with respect to the descending node.

The descending node pairs with the ascending node as intersecting points of Earth’s orbit by the lunar orbit. The two nodes reflect the approximately 5.1 degree tilt of the lunar orbit with respect to Earth’s orbit. The ascending node indicates the moon’s orbital crossing to the north of Earth’s orbit. The descending node marks the lunar orbital crossing to the south of Earth’s orbit.

A Saros cycle of periodicity and recurrence of eclipses approximates 6,585.3 days (18 years 11 days 8 hours). Each series produces 70 or more lunar eclipses, each separated by a Saros cycle. The timeline for a series typically spans 12 to 15 centuries.

Saros series 125 spans 1,280.14 years, according to NASA Eclipse Web Site. Saros series 125 lasts 14 centuries. Saros series 125 spans the 12th through 25th centuries.

Lunar eclipses in Saros cycle 125 occur in the sequence order of 17 penumbral lunar eclipses, 13 partial lunar eclipses, 26 total lunar eclipses, nine partial lunar eclipses and seven penumbral eclipses. Total lunar eclipses claim the most number of Saros 125 eclipses, with a total of 26 occurrences. Penumbral lunar eclipses account for the second most frequent lunar eclipse type in the series, with a total of 24 occurrences.

The 12th century’s penumbral eclipse of July 17, 1163, initiated Saros cycle 125. This event experienced its greatest eclipse over the South Pacific Ocean, southeast of the Kingdom of Tona.

The 12th century’s opening Saros 125 eclipse is dated according to the Julian Calendar. The NASA Eclipse Web Site’s Key to Catalog of Lunar Eclipses notes the use of the Julian Calendar for dates before Oct. 4, 1582, and the application of the Gregorian Calendar for dates after Oct. 15, 1582.

The 25th century’s penumbral eclipse of Wednesday, Sept. 9, 2443, ends Saros series 125. This eclipse numbers as the seventh in Saros 125’s closing set of seven penumbral lunar eclipses. This event's greatest eclipse will take place over the South Indian Ocean, southwest of Sri Lanka, east of Kenya and west of Sumatra.

The Tuesday, Dec. 21, 2010, total lunar eclipse occurs as number 18 within the sequence of 26 total lunar eclipses in Saros series 125. This event's greatest eclipse occurs over the North Pacific Ocean, west of Mexico's Baja California Sur (Estado Libre y Soberano de Baja California Sur; Free and Sovereign State of South Lower California).

The total lunar eclipse of Wednesday, Dec. 9, 1992, is the immediate predecessor of the Dec. 21, 2010, total lunar eclipse. The Dec. 9, 1992, total lunar eclipse appears as number 17 in the total lunar eclipse sequence and as number 47 in Saros 125’s lineup of 72 eclipses. This event experienced its greatest eclipse over southern Algeria's Tamanrasset (Berber: Tamanghasset) Province.

The total lunar eclipse of Sunday, Dec. 31, 2028, will appear as the successor of the Dec. 21, 2010, total lunar eclipse in Saros cycle 125. This eclipse numbers as 19 within the sequence of 26 total lunar eclipses and as 49 in the series’ lineup of 72 eclipses. This event's greatest eclipse will take place over Southern China's Guangxi Zhuang Autonomous Region.

The takeaway for the Dec. 21, 2010, total lunar eclipse is that the event occurs as number 18 in Saros series 125’s set of 26 total lunar eclipses and as number 48 in the series’ lineup of 72 lunar eclipses.

Penumbral lunar eclipse of Sept. 9, 2443, will close Saros 125’s lineup of 72 lunar eclipse: "Permission is freely granted to reproduce this data when accompanied by an acknowledgment, Eclipse Predictions by Fred Espenak and Jean Meeus (NASA's GSFC)," via NASA Eclipse Web Site

Acknowledgment

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

Image credits:

Penumbral lunar eclipse of July 17, 1163, opened Saros 125’s lineup of 72 lunar eclipses: "Permission is freely granted to reproduce this data when accompanied by an acknowledgment, Eclipse Predictions by Fred Espenak and Jean Meeus (NASA's GSFC)," via NASA Eclipse Web Site @ https://eclipse.gsfc.nasa.gov/5MCLEmap/1101-1200/LE1163-07-17N.gif

Penumbral lunar eclipse of Sept. 9, 2443, will close Saros 125’s lineup of 72 lunar eclipses: "Permission is freely granted to reproduce this data when accompanied by an acknowledgment, Eclipse Predictions by Fred Espenak and Jean Meeus (NASA's GSFC)," via NASA Eclipse Web Site @ https://eclipse.gsfc.nasa.gov/5MCLEmap/2401-2500/LE2443-09-09N.gif

For further information:

Espenak, Fred. “2010 Dec 21: Total Lunar Eclipse.” NASA Eclipse Web Site > Eclipses During 2010.
Available via NASA Eclipse Web Site @ https://eclipse.gsfc.nasa.gov/OH/OH2010.html

Espenak, Fred. “Key to Catalog of Lunar Eclipse Saros Series." NASA Eclipse Web Site > Lunar Eclipses > Catalog of Lunar Eclipse Saros Series > Saros Series 125.
Available via NASA Eclipse Web Site @ https://eclipse.gsfc.nasa.gov/LEsaros/LEsaroscatkey.html

Espenak, Fred. “Penumbral 1163 Jul 17.” NASA Eclipse Web Site > Lunar Eclipses > Catalog of Lunar Eclipse Saros Series > Lunar Eclipses of Saros Series 1 to 180: Summary of Saros Series 101 to 125: 125 > Saros Series 125: 01 -36 1163 Jul 17.
Available via NASA Eclipse Web Site @ https://eclipse.gsfc.nasa.gov/5MCLEmap/1101-1200/LE1163-07-17N.gif

Espenak, Fred. “Penumbral 2443 Sep 09.” NASA Eclipse Web Site > Lunar Eclipses > Catalog of Lunar Eclipse Saros Series > Lunar Eclipses of Saros Series 1 to 180: Summary of Saros Series 101 to 125: 125 > Saros Series 125: 72 35 2443.
Available via NASA Eclipse Web Site @ https://eclipse.gsfc.nasa.gov/5MCLEmap/2401-2500/LE2443-09-09N.gif

Espenak, Fred. “Total 1992 Dec 09." NASA Eclipse Web Site > Lunar Eclipses > Catalog of Lunar Eclipse Saros Series > Lunar Eclipses of Saros Series 1 to 180: Summary of Saros Series 101 to 125: 47 10 1992 Dec 09.
Available @ https://eclipse.gsfc.nasa.gov/5MCLEmap/1901-2000/LE1992-12-09T.gif

Espenak, Fred. “Total 2028 Dec 31." NASA Eclipse Web Site > Lunar Eclipses > Catalog of Lunar Eclipse Saros Series > Lunar Eclipses of Saros Series 1 to 180: Summary of Saros Series 101 to 125: 49 12 2028 Dec 31.
Available via NASA Eclipse Web Site @ https://eclipse.gsfc.nasa.gov/5MCLEmap/2001-2100/LE2028-12-31T.gif

Espenak, Fred; Jean Meeus. "Saros Series 125." NASA Eclipse Web Site > Lunar Eclipses > Catalog of Lunar Eclipse Saros Series > Lunar Eclipses of Saros Series 1 to 180.
Available via NASA Eclipse Web Site @ https://eclipse.gsfc.nasa.gov/LEsaros/LEsaros125.html

Marriner, Derdriu. "One Exeligmos Unites Dec. 21, 2010, and Nov. 18, 1956, Lunar Eclipses." Earth and Space News. Wednesday, Dec. 1, 2010.
Available @ https://earth-and-space-news.blogspot.com/2010/12/one-exeligmos-unites-dec-21-2010-and.html

Smith, Ian Cameron. "Penumbral Lunar Eclipse of 9 Sep, 2443 AD." Moon Blink > Hermit Eclipse > Eclipse Database > Full Lunar Catalog >2001-3000 AD > 2401 AD > 2441-2460 AD. Available @ https://moonblink.info/Eclipse/eclipse/2443_09_09

Smith, Ian Cameron. "Penumbral Lunar Eclipse of 17 Jul, 1163 AD." Moon Blink > Hermit Eclipse > Eclipse Database > Full Lunar Catalog >1001-2000 AD > 1101 AD > 1161-1180 AD.
Available @ https://moonblink.info/Eclipse/eclipse/1163_07_17

Smith, Ian Cameron. "Total Lunar Eclipse of 9 Dec, 1992 AD." Moon Blink > Hermit Eclipse > Eclipse Database > Full Lunar Catalog >1001-2000 AD > 1901 AD > 1981-2000 AD.
Available @ https://moonblink.info/Eclipse/eclipse/1992_12_09

Smith, Ian Cameron. "Total Lunar Eclipse of 21 Dec, 2010 AD." Moon Blink > Hermit Eclipse > Eclipse Database > Full Lunar Catalog >2001-3000 AD > 2001 AD > 2001-2020 AD.
Available @ https://moonblink.info/Eclipse/eclipse/2010_12_21

Smith, Ian Cameron. "Total Lunar Eclipse of 31 Dec, 2028 AD." Moon Blink > Hermit Eclipse > Eclipse Database > Full Lunar Catalog >2001-3000 AD > 2001 AD > 2021-2040 AD.
Available @ https://moonblink.info/Eclipse/eclipse/2028_12_31

Walker, John. “Lunar Perigee and Apogee Calculator.” Fourmilab Switzerland > Earth and Moon Viewer.
Available @ https://www.fourmilab.ch/earthview/pacalc.html

One Exeligmos Unites Dec. 21, 2010, and Nov. 18, 1956, Lunar Eclipses

Summary: One exeligmos unites the Tuesday, Dec. 21, 2010, and Sunday, Nov. 18, 1956, total lunar eclipses in the Saros lunar 125 series of 72 similar eclipses.

Total lunar eclipse of Tuesday, Dec. 21, 2010, frames an exeligmos cycle (approximately 54 years 34 days) with total lunar eclipse of Sunday, Nov. 18, 1956, in lunar Saros 125 series: "Permission is freely granted to reproduce this data when accompanied by an acknowledgment, Eclipse Predictions by Fred Espenak and Jean Meeus (NASA's GSFC)," via NASA Eclipse Web Site

One exeligmos unites the Tuesday, Dec. 21, 2010, total lunar eclipse with the Sunday, Nov. 18, 1956, total lunar eclipse in the Saros lunar 125 series of 72 similar eclipses.

The Saros series of lunar and solar eclipses is based upon the Saros cycle. A Saros cycle approximates 6,585.3 days (18 years 11 days 8 hours). A Saros series comprises 70 or more eclipses, with each eclipse separated from its predecessor by one Saros cycle. A Saros series typically spans 12 to 15 centuries.

A Saros series recognizes similarities in occurrence in the series’ component eclipses. Every eclipse in a specific Saros series shares the geometry of association with the same one of the lunar orbit’s two nodes.

The lunar orbit’s ascending and descending nodes demark the two intersecting points of the lunar orbit around Earth with Earth’s orbital path around the sun. The nodes arise from the approximately 5.1 degree tilt of the moon’s orbit with respect to Earth’s orbit.

Even numbers are assigned to those Saros series with lunar eclipses occurring at the ascending node. Eclipses in even-numbered Saros series experience southward lunar movement with respect to the ascending node.

Those Saros series composed of lunar eclipses associated with the descending node receive odd numbers. Eclipses in odd-numbered Saros series exhibit northward lunar movement with respect to the descending node.

Every triple Saros cycle, a Saros series approximately revisits the same geographic region. The Saros cycle’s equivalence, at 18 years 11 days 8 hours, to less than a whole number of days accounts the cycle’s ending before Earth has completed a full rotation. The cycle’s ending on one-third of a day (eight hours) expresses as the Earth’s rotation of 120 degrees. The cycle’s 120-degree increments with each succeeding eclipse occasions the series’ return to the same geographic region every triple Saros cycle.

Three Saros cycles within a Saros series approximates 54 years 34 days. Greco-Roman astronomer and mathematician Claudius Ptolemaeus (ca. 100-ca. 170 CE) noted in chapter 2, On the Periods of the Moon, in Book 4 of his Almagest that ancient astronomers designated the triple Saros cycle with the term exeligmos. Astronomy historian Gerald James Toomer (born Nov. 23, 1934) explained in his annotated translation of Ptolemy’s astronomical treatise that exeligmos (Ancient Greek: ἐξέλιγμος) means “turn of the wheel.”

The total lunar eclipse of Sunday, Nov. 18, 1956, was centered on the northeastern Pacific Ocean, off the coast of northwestern Mexico. Visibility of the entire eclipse was available to North America, northwestern and parts of western central South America, northernmost Europe (Iceland, Norway’s Svalbard archipelago, parts of northwesternmost Russia) and northernmost Asia (Russian Far East). The Arctic Ocean, parts of the northwestern Atlantic Ocean and the Pacific Ocean (northeastern; northwestern Pacific’s marginal Bering Sea; parts of the southeastern Pacific) comprised the oceanic regions of entire eclipse visibility for the November 1956 total lunar eclipse.

The total lunar eclipse of Tuesday, Dec. 21, 2010, centers on the northeastern Pacific Ocean, west of the Baja California Peninsula. Entire eclipse visibility is available to North America, parts of northwestern South America (western parts of Venezuela, Colombia, Ecuador and Peru), northernmost Europe (Iceland; Norway’s Svalbard archipelago; northern Scandinavian Peninsula; northwestern Russia) and northern Asia (northern Russia). The oceanic regions of entire eclipse visibility comprise the Arctic Ocean, parts of the northwestern Atlantic Ocean and the Pacific Ocean (northeastern; parts of the northwestern; parts of the southeastern).

Ecliptic occurrence at the descending lunar node characterizes Saros 125, the Saros lunar series to which the November 1956 and December 2010 total lunar eclipses belong. Each successive lunar eclipse in the lunar Saros 125 series displays lunar movement northward of the descending node.

Lunar Saros series 125 requires 1,280.14 years to produce its 72 similarly occurring lunar eclipses. Saros 125 began with the 12th century’s penumbral eclipse of Wednesday, July 17, 1163. Saros 125 will end in the 25th century with the penumbral eclipse of Wednesday, Sept. 9, 2443.

The takeaway for the one exeligmos that unites the Tuesday, Dec. 21, 2010, and Sunday, Nov. 18, 1956, total lunar eclipses in the Saros lunar 125 series of 72 similar eclipses is that an exeligmos cycle of approximately 54 years 34 days explains the return of the December 2010 lunar eclipse to approximately the same visibility regions as those favored by the November 1956 lunar eclipse.

An exeligmos cycle (approximately 54 years 34 days) accounts for the similar geographic region visibility that the total lunar eclipse of Sunday, Nov. 18, 1956, shares with the total lunar eclipse of Tuesday, Dec. 21, 2010, in lunar Saros 125 series: "Permission is freely granted to reproduce this data when accompanied by an acknowledgment, Eclipse Predictions by Fred Espenak and Jean Meeus (NASA's GSFC)," via NASA Eclipse Web Site

Acknowledgment

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

Image credits:

Total lunar eclipse of Tuesday, Dec. 21, 2010, frames an exeligmos cycle (approximately 54 years 34 days) with total lunar eclipse of Sunday, Nov. 18, 1956, in lunar Saros 125 series: "Permission is freely granted to reproduce this data when accompanied by an acknowledgment, Eclipse Predictions by Fred Espenak and Jean Meeus (NASA's GSFC)," via NASA Eclipse Web Site @ https://eclipse.gsfc.nasa.gov/5MCLEmap/2001-2100/LE2010-12-21T.gif

An exeligmos cycle (approximately 54 years 34 days) accounts for the similar geographic region visibility that the total lunar eclipse of Sunday, Nov. 18, 1956, shares with the total lunar eclipse of Tuesday, Dec. 21, 2010, in lunar Saros 125 series: "Permission is freely granted to reproduce this data when accompanied by an acknowledgment, Eclipse Predictions by Fred Espenak and Jean Meeus (NASA's GSFC)," via NASA Eclipse Web Site @ https://eclipse.gsfc.nasa.gov/5MCLEmap/1901-2000/LE1956-11-18T.gif

For further information:

Espenak, Fred. “2010 Dec 21: Total Lunar Eclipse.” NASA Eclipse Web Site > Eclipses During 2010.
Available @ https://eclipse.gsfc.nasa.gov/OH/OH2010.html

Espenak, Fred. “Key to Catalog of Lunar Eclipse Saros Series." NASA Eclipse Web Site > Lunar Eclipses > Catalog of Lunar Eclipse Saros Series > Saros Series 125.
Available @ https://eclipse.gsfc.nasa.gov/LEsaros/LEsaroscatkey.html

Espenak, Fred. “Penumbral 1163 Jul 17.” NASA Eclipse Web Site > Lunar Eclipses > Catalog of Lunar Eclipse Saros Series > Saros Series 125.
Available @ https://eclipse.gsfc.nasa.gov/5MCLEmap/1101-1200/LE1163-07-17N.gif

Espenak, Fred. “Penumbral 2443 Sep 09.” NASA Eclipse Web Site > Lunar Eclipses > Catalog of Lunar Eclipse Saros Series > Saros Series 125.
Available @ https://eclipse.gsfc.nasa.gov/5MCLEmap/2401-2500/LE2443-09-09N.gif

Espenak, Fred. “Total 1956 Nov 18." NASA Eclipse Web Site > Lunar Eclipses > Lunar Eclipse Links > Catalog of Lunar Eclipse Saros Series > Saros Series 125.
Available @ https://eclipse.gsfc.nasa.gov/5MCLEmap/1901-2000/LE1956-11-18T.gif

Espenak, Fred. "Total 2010 Dec 21." NASA Eclipse Web Site > Lunar Eclipses > Catalog of Lunar Eclipses: Catalog of Lunar Eclipse Saros Series > Lunar Eclipses of Saros Series 1 to 180: Summary of Saros Series 101 to 125: 125 > Saros Series 125: 48 11 2010 Dec 21.
Available via NASA Eclipse Web Site @ https://eclipse.gsfc.nasa.gov/5MCLEmap/1101-1200/LE1163-07-17N.gif

Espenak, Fred. “Total Lunar Eclipse of 1956 Nov 18.” EclipseWise > Solar Eclipses > Six Millennium Catalog of Lunar Eclipses -2999 to +3000 (3000 BCE to 3000 CE) > 1901 to 2000 (1901 CE to 2000 CE).
Available @ http://eclipsewise.com/lunar/LEprime/1901-2000/LE1956Nov18Tprime.html

Espenak, Fred. “Total Lunar Eclipse of 2010 Dec 21.” EclipseWise > Solar Eclipses > Six Millennium Catalog of Lunar Eclipses -2999 to +3000 (3000 BCE to 3000 CE) > 2001 to 2100 (2001 CE to 2100 CE).
Available @ http://eclipsewise.com/lunar/LEprime/2001-2100/LE2010Dec21Tprime.html

Espenak, Fred; Jean Meeus. "Saros Series 125." NASA Eclipse Web Site > Lunar Eclipses > Catalog of Lunar Eclipse Saros Series.
Available @ https://eclipse.gsfc.nasa.gov/LEsaros/LEsaros125.html

Freeth, Tony. “Eclipse Prediction on the Ancient Greek Astronomical Calculating Machine Known as the Antikythera Mechanism.” PLOS ONE. July 30, 2014. DOI: doi.org/10.1371/journal.pone.0103275
Available via PLOS @ https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0103275#references

Toomer, G.J. [Gerald James]. Ptolemy’s Almagest: Book IV, page 175, note 8. London, England: Gerald Duckworth & Co. Ltd., 1984.
Available via Internet Archive @ https://archive.org/details/PtolemysAlmagestPtolemyClaudiusToomerG.5114/page/n182