Jan. 31, 2018, Blue Moon Total Lunar Eclipse Belongs to Saros Cycle 124

Summary: The Wednesday, Jan. 31, 2018, blue moon total lunar eclipse belongs to Saros cycle 124, a series of 73 lunar eclipses linked by similar geometries

Saros 124’s blue moon total lunar eclipse of Wednesday, Jan. 31, 2018, occurs as the 49th in the 73-member lineup of Saros cycle 124: "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 Wednesday, Jan. 31, 2018, blue moon total lunar eclipse belongs to Saros cycle 124, which comprises a series of 73 lunar eclipses linked by similar geometries over a cycle of approximately 6,585.3 days (18 years 11 days 8 hours).

Saros 124 lunar eclipses share occurrences at the lunar orbit’s ascending node. Also known as the lunar orbit’s north node, the ascending node marks the point of the moon’s crossing from south to north of the Earth’s orbital plane.

January 2018’s blue moon total lunar eclipse appears as number 49 in the lineup of Saros 124 lunar eclipses. The family, known as a series, of Saros 124 endures for 1,298.17 years. Saros 124 opens Aug. 17, 1152, with a penumbral eclipse in proximity to the northern edge of the fainter, outer part of Earth’s shadow, known as the penumbra (Latin: paene, “almost, nearly” + umbra, “shadow”). Saros 124 closes Oct. 21, 2450, with a penumbral eclipse tapping the penumbra’s southern edge.

Saros 124’s lineup of 73 lunar eclipses features five sequences. The initial sequence comprises 20 penumbral eclipses. The second sequence is composed of eight partial eclipses. The third sequence presents 28 total eclipses. The fourth sequence represents eight partial eclipses. The fifth and final sequence comprises nine penumbral eclipses.

The blue moon total lunar eclipse on Wednesday, Jan. 31, 2018, holds place 21 in the sequence of 28 total lunar eclipses. The sequence’s first total lunar eclipse occurred Monday, June 25, 1627. The sequence’s last total lunar eclipse happens Saturday, April 18, 2144.

Retired NASA astrophysicist Fred Espenak, known as “Mr. Eclipse,” details January 2018’s Saros 124 total lunar eclipse as having a duration of 317.3 minutes for the penumbral phase. Partiality lasts 202.8 minutes, and totality endures for 76.1 minutes.

Saros 124’s first total lunar eclipse displayed a penumbral phase of 329.2 minutes. The June 25, 1627, total lunar eclipse presented 201.0 minutes of partiality and 35.9 minutes of totality. The June 1627 event occupied place 29 in Saros 124’s lineup of 73 lunar eclipses.

Saros 124’s final total lunar eclipse expects a penumbral phase of 303.0 minutes. The April 18, 2144, total lunar eclipse has a predicted partiality duration of 187.0 minutes. Totality spans 7.6 minutes. The April 2144 event holds place 56 in Saros 124’s lineup of 73 lunar eclipses.

Saros 124’s total lunar eclipse of Aug. 30, 1765, claims longest duration of totality, at 1 hour 41 minutes 27 seconds, in the cycle's sequence of 28 total lunar eclipses. August 1765’s lunar event occurred as the sequence’s seventh total lunar eclipse and as number 35 among Saros 124’s lineup of 73 lunar eclipses.

Saros 124’s total lunar eclipse of April 18, 2144, closes the sequence with the shortest predicted duration of totality, at 00 hours 7 minutes 34 seconds. The second shortest duration of totality, at 35.9 minutes, is claimed by the sequence’s opening total lunar eclipse of June 25, 1657.

January 2018’s Saros 124 total lunar eclipse holds place 19 between the sequence’s longest to shortest enduring totality phases.

January 2018’s immediate predecessor in Saros 124’s total lunar eclipse sequence occurred Friday, Jan. 21, 2000. January 2018’s successor in the sequence appears Monday, Feb. 11, 2036.

Within Saros 124’s sequence of 28 total lunar eclipses, January 2018’s event numbers as the second of the sequence’s two blue moon total lunar eclipses. The sequences first blue moon total lunar eclipse occurred Aug. 30, 1765. August 1765 opened with a full moon on Thursday, Aug. 1, and then phased Friday, Aug. 30, into a second full moon, known as a blue moon, that coincided with 1765’s Saros 124 total lunar eclipse.

January 2018’s blue moon total lunar eclipse is the first of the year’s two total lunar eclipses. The second total lunar eclipse happens Friday, July 27, 2018. July’s total lunar eclipse belongs to Saros 129.

The takeaways for the Jan. 31, 2018, blue moon total lunar eclipse are the event’s membership in Saros cycle 124 and its status as the second of only two blue moon total lunar eclipses within Saros 124’s sequence of 28 total lunar eclipses.

January 2018’s lunar eclipse joins August 1765’s total lunar eclipse as the only two blue moon total lunar eclipses in Saros 124’s total lunar eclipse sequence; Saros 124’s blue moon total lunar eclipse, Aug. 30, 1765: "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:

aros 124’s blue moon total lunar eclipse of Wednesday, Jan. 31, 2018, occurs as the 49th in the 73-member lineup of Saros cycle 124: "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/LE2018-01-31T.gif

January 2018’s lunar eclipse joins August 1765’s total lunar eclipse as the only two blue moon total lunar eclipses in Saros 124’s total lunar eclipse sequence: "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/1701-1800/LE1765-08-30T.gif

For further information:

Dickinson, David. “Predicting Eclipses: How Does the Saros Cycle Work?” Universe Today > Guide to Space. March 26, 2015. Updated Dec. 23, 2015.
Available @ https://www.universetoday.com/119444/predicting-eclipses-how-does-the-saros-cycle-work/

Espenak, Fred. “Catalog of Lunar Eclipse Saros Series.” NASA Eclipse Web Site > Lunar Eclipses > Lunar Eclipse Catalogs.
Available @ https://eclipse.gsfc.nasa.gov/LEsaros/LEsaroscat.html

Espenak, Fred. “Eclipses and the Saros.” NASA Eclipse Web Site.
Available @ https://eclipse.gsfc.nasa.gov/SEsaros/SEsaros.html

Espenak, Fred. “Eclipses During 2018.” EclipseWise > Recent and Upcoming Lunar Eclipses.
Available @ http://www.eclipsewise.com/oh/ec2018.html

Espenak, Fred. “Key to Saros Catalog of Lunar Eclipses.” EclipseWise > Lunar Eclipses > Saros -29 to 190.
Available @ http://www.eclipsewise.com/lunar/LEhelp/LEsarcatkey.html

Espenak, Fred. “Periodicity of Lunar Eclipses.” NASA Eclipse Web Site > Lunar Eclipses > Special Interest > Eclipses and the Saros.
Available @ https://eclipse.gsfc.nasa.gov/LEsaros/LEperiodicity.html

Espenak, Fred. “Saros 124.” EclipseWise > Recent and Upcoming Lunar Eclipses > Eclipses During 2018.
Available @ http://www.eclipsewise.com/lunar/LEsaros/LEsaros124.html

Marriner, Derdriu. "Blue Moon Month January 2018 Opens New York With Two Full Moons." Earth and Space News. Wednesday, Dec. 27, 2017.
Available @ https://earth-and-space-news.blogspot.com/2017/12/blue-moon-month-january-2018-opens-new.html

van den Bergh, George. Periodicity and Variation of Solar (and Lunar) Eclipses. Haarlem, Netherlands: H.D. Tjeenk Willink, 1955.