One Exeligmos Links Nov. 28, 2012, and Dec. 31, 2066, Lunar Eclipses

Summary: One exeligmos links the Wednesday, Nov. 28, 2012, and Friday, Dec. 31, 2066, penumbral lunar eclipses in the Saros lunar 145 series of 71 similar eclipses.

Penumbral lunar eclipse of Wednesday, Nov. 28, 2012, offers eclipse visibility regions that will be revisited in an exeligmos cycle (approximately 54 years 34 days) by the penumbral lunar eclipse of Friday, Dec. 31, 2066, in lunar Saros 145 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 links the Wednesday, Nov. 28, 2012, penumbral lunar eclipse with the Friday, Dec. 31, 2066, penumbral lunar eclipse in the Saros lunar 145 series of 71 similar eclipses.

The Saros cycle decides the periodicity and recurrence of lunar and solar eclipses. A Saros cycle approximately equates to 6,585.3 days (18 years 11 days 8 hours). A Saros cycle separates each of the similar eclipses that are grouped together into a family, known as a series. Each series produces 70 or more eclipses over a typical timeline of 12 to 15 centuries.

A Saros series emphasizes similar occurrences in the series’ constituent eclipses. Each eclipse in a particular Saros series exhibits the shared geometry of occurrence at the same lunar node.

The approximately 5.1 degree tilt of the lunar orbit with respect to Earth’s orbit account for two nodes in the lunar orbit. The nodes mark the two orbital paths’ points of intersection.

The ascending node signals the moon’s movement southward of the node with each successive lunar eclipse in the series. Lunar series associated with the ascending node receive even-numbered Saros designations.

The descending node announces the moon’s movement northward of the node with each subsequent lunar eclipse in the series. Odd-numbered Saros designations are assigned to lunar series occurring at the descending node.

Each Saros cycle ends before the completion of a full rotation by Earth. The cycle’s value of 18 years 11 days 8 hours places the end at one-third of a full day (eight hours out of 24) and at one-third of a full rotation (120 degrees out of 360).

The cumulative effect of the one-third rotation demarcation at the end of each cycle explains the phenomenon of the exeligmos (Ancient Greek: ἐξέλιγμος, “entire evolution, turn of the wheel”) cycle. An exeligmos cycle approximates 54 years 34 days. Every three successive cycles within a particular Saros series, an eclipse returns to approximately the same geographic region that was favored 54 years 34 days earlier.

The penumbral lunar eclipse of Wednesday, Nov. 28, 2012, will be centered on the northwestern Pacific Ocean’s marginal Philippine Sea, south of the East Asian island country of Japan and northeast of the archipelagic Republic of the Philippines. Entire eclipse visibility is available to northern North America (Alaska, western Canada, the Canadian Arctic Archipelago, most of Greenland), northern Europe (parts of Finnish and Norwegian Scandinavian Peninsula, Norway’s Svalbard archipelago, northwestern Russia), Asia (most of Central and South Asia, all of continental and maritime East Asia) and Australia. Oceanic regions of entire eclipse visibility include the Arctic Ocean, most of the Western Pacific Ocean, much of the East Indian Ocean and part of the Southern Ocean.

The penumbral lunar eclipse of Friday, Dec. 31, 2066, will be centered on the northwestern Pacific Ocean, south of Japan and northeast of the Philippines. This eclipse is centered to the east of the November 2012 penumbral lunar eclipse. Observers in northern North America (Alaska, western and north central Canada, the Canadian Arctic Archipelago, most of Greenland), northern Europe (parts of Norwegian and Finnish Scandinavian Peninsula, Norway’s Svalbard archipelago, northwestern Russia), Asia (parts of South Asia, most of Central Asia, all of continental and maritime East Asia) and Australia will experience entire eclipse visibility. Entire eclipse visibility will be available to the oceanic regions of the Arctic Ocean, parts of the North Atlantic Ocean, parts of the East Indian Ocean, the Pacific Ocean (all of the western, parts of the central and northeastern Pacific) and part of the Southern Ocean.

The penumbral lunar eclipses of Wednesday, Nov. 28, 2012, and Friday, Dec. 31, 2066, belong to lunar Saros series 145. All Saros lunar series 145 eclipses occur at the descending lunar node.

Saros 145 produces 71 similarly occurring lunar eclipses over a timeline of 1,262.11 years. Saros 145 opened with the 19th century’s penumbral eclipse of Saturday, Aug. 11, 1832. Saros 145 ends with the 31st century’s penumbral lunar eclipse of Sunday, Sept. 16, 3094.

The takeaway for the one exeligmos that links the Wednesday, Nov. 28, 2012, penumbral lunar eclipse with the Friday, Dec. 31, 2066, penumbral lunar eclipse in the Saros lunar 145 series of 71 similar eclipses is that an exeligmos cycle of approximately 54 years 34 days explains the approximately similar visibility regions availed by the November 2012 and December 2066 penumbral lunar eclipses.

The exeligmos cycle (approximately 54 years 34 days) that elapses between the penumbral lunar eclipses of Wednesday, Nov. 28, 2012, and Friday, Dec. 31, 2066, accounts for the similar geographic region visibility shared by the two eclipses in lunar Saros 145 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:

Penumbral lunar eclipse of Wednesday, Nov. 28, 2012, offers eclipse visibility regions that will be revisited in an exeligmos cycle (approximately 54 years 34 days) by the penumbral lunar eclipse of Friday, Dec. 31, 2066, in lunar Saros 145 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/LE2012-11-28N.gif

The exeligmos cycle (approximately 54 years 34 days) that elapses between the penumbral lunar eclipses of Wednesday, Nov. 28, 2012, and Friday, Dec. 31, 2066, accounts for the similar geographic region visibility shared by the two eclipses in lunar Saros 145 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/LE2066-12-31N.gif

For further information:

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 1832 Aug 11.” NASA Eclipse Web Site > Lunar Eclipses > Lunar Eclipse Page: Lunar Eclipse Catalogs: Catalog of Lunar Eclipse Saros Series > Catalog of Lunar Eclipse Saros Series: Lunar Eclipses of Saros Series 1 to 180: Summary of Saros Series 126 to 150: 145 > Catalog of Lunar Eclipse Saros Series: Saros Series 145: 01 -33 1832 Aug 11.
Available via NASA Eclipse Web Site @ https://eclipse.gsfc.nasa.gov/5MCLEmap/1801-1900/LE1832-08-11N.gif

Espenak, Fred. “Penumbral 2012 Nov 28.” NASA Eclipse Web Site > Lunar Eclipses > Lunar Eclipse Page: Lunar Eclipse Catalogs: Catalog of Lunar Eclipse Saros Series > Catalog of Lunar Eclipse Saros Series: Lunar Eclipses of Saros Series 1 to 180: Summary of Saros Series 126 to 150: 145 > Catalog of Lunar Eclipse Saros Series: Saros Series 145: 11 -23 2012 Nov 28.
Available via NASA Eclipse Web Site @ https://eclipse.gsfc.nasa.gov/5MCLEmap/2001-2100/LE2012-11-28N.gif

Espenak, Fred. “Penumbral 2066 Dec 31.” NASA Eclipse Web Site > Lunar Eclipses > Lunar Eclipse Page: Lunar Eclipse Catalogs: Catalog of Lunar Eclipse Saros Series > Catalog of Lunar Eclipse Saros Series: Lunar Eclipses of Saros Series 1 to 180: Summary of Saros Series 126 to 150: 145 > Catalog of Lunar Eclipse Saros Series: Saros Series 145: 14 -20 2066 Dec 31.
Available via NASA Eclipse Web Site @ https://eclipse.gsfc.nasa.gov/5MCLEmap/2001-2100/LE2066-12-31N.gif

Espenak, Fred. “Penumbral Lunar Eclipse of 2012 Nov 28.” EclipseWise > Lunar Eclipses > Lunar Eclipse Links > Six Millennium Catalog of Lunar Eclipses -2999 to +3000 (3000 BCE to 3000 CE) > 2001 to 2100 (2001 CE to 2100 CE).
Available via EclipseWise @ http://eclipsewise.com/lunar/LEprime/2001-2100/LE2012Nov28Nprime.html

Espenak, Fred. “Penumbral Lunar Eclipse of 2066 Dec 31.” EclipseWise > Lunar Eclipses > Lunar Eclipse Links > Six Millennium Catalog of Lunar Eclipses -2999 to +3000 (3000 BCE to 3000 CE) > 2001 to 2100 (2001 CE to 2100 CE).
Available via EclipseWise @ http://eclipsewise.com/lunar/LEprime/2001-2100/LE2066Dec31Nprime.html

Espenak, Fred; Jean Meeus. "Saros Series 145." NASA Eclipse Web Site > Lunar Eclipses > Catalog of Lunar Eclipse Saros Series.
Available via NASA Eclipse Web Site @ https://eclipse.gsfc.nasa.gov/LEsaros/LEsaros145.html

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

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