First 2018 Eclipse Is Blue Moon Total Lunar Eclipse Wednesday, Jan. 31

Summary: The first 2018 eclipse is the blue moon total lunar eclipse Wednesday, Jan. 31, happening during January’s second full moon, known as a blue moon.

graphics and details of blue moon total lunar eclipse Wednesday, Jan. 31, 2018: "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 2018 eclipse is a blue moon total lunar eclipse Wednesday, Jan. 31, that happens during January’s second full moon, known as a blue moon.

The blue moon lunar eclipse of Wednesday, Jan. 31, begins at 10:51:15 Coordinated Universal Time (12:51:15 a.m. Hawaii-Aleutian Standard Time) with the instant of first exterior contact between the moon and Earth’s penumbra, the lighter, outer region of Earth’s shadow. The event ends at 16:08:27 UTC (6:08:27 a.m. HAST) with the instant of last exterior contact between moon and Earth’s penumbra. The blue moon lunar eclipse lasts for 5 hours 17 minutes 12 seconds.

The partial phase of the blue moon total lunar eclipse Wednesday, Jan. 31, begins at 11:48:27 UTC (1:48:27 a.m. HAST) with the instant of first exterior contact between the moon and Earth’s umbra, the darker, inner region of Earth’s shadow. Partiality ends at 15:11:11 UTC (5:11:11 a.m. HAST) with the instant of last exterior contact between the moon and Earth’s umbra. Partiality’s time span is 3 hours 22 minutes 44 seconds.

The total phase of the blue moon total lunar eclipse Wednesday, Jan. 31, begins at 12:51:47 UTC (2:51:47 a.m. HAST) with the instant of first interior contact between the moon and Earth’s umbra. Totality ends at 14:07:51 UTC (4:07:51 a.m. HAST) with the instant of last interior contact between the moon and Earth’s umbra. Totality’s time span is 1 hour 16 minutes 4 seconds.

For lunar eclipses, greatest eclipse references the instant of the moon’s closest passage to the axis of Earth’s shadow. The greatest eclipse for the blue moon total lunar eclipse Wednesday, Jan. 31, takes place at 13:29:51 UTC (3:29:51 a.m. HAST). Retired NASA astrophysicist Fred Espenak's EclipseWise web site places the greatest eclipse's occurrence over the South Pacific Ocean, about 1,800 miles (2,900 kilometers) west of the Hawaiian Islands.

The blue moon total lunar eclipse Wednesday, Jan. 31, centers on the Pacific Ocean. Oceanically, entire eclipse visibility also favors the Arctic Ocean. Continentally, eclipse visibility from beginning to end favors central and eastern Asia, most of Australia and far northern North America.

In North America, Canada experiences entire eclipse visibility throughout Yukon Territory and in much of the Northwest Territories and Nunavut. Most of British Columbia and the northwestern corner of Alberta also enjoy entire eclipse visibility. Entire eclipse visibility favors only two U.S. states: Alaska on the North American mainland and Hawaii in the Pacific Ocean.

Arctic Ocean and Pacific Ocean islands are favorably sited for entire eclipse visibility. Northern Greenland joins Canada’s, Norway’s and Russia’s Arctic islands in the entire eclipse experience. In Maritime Southeast Asia, all of New Guinea and the Philippines and much of Borneo participate in entire eclipse visibility. Other Pacific island nations favored by entire eclipse visibility include Japan, New Zealand and Samoa.

Oceanic areas with no eclipse visibility at all include most of the Atlantic Ocean and the Southern Ocean. Continentally, most of the continents of Africa, Antarctica, Europe and South America are excluded for eclipse visibility.

The blue moon total lunar eclipse Wednesday, Jan. 31, opens the 2018 eclipse quintet of two total lunar eclipses and three partial solar eclipses. The year’s second total lunar eclipse happens Friday, July 27, and favors the Indian Ocean and adjacent continents.

The year’s first partial solar eclipse succeeds 2018’s first total lunar eclipse. The first partial solar eclipse takes place Thursday, Feb. 15, as a Southern Hemisphere event favoring Antarctica and southern South America. The year’s second partial solar eclipse happens Friday, July 13, as a Southern Hemisphere event favoring the Southern Ocean and southeastern Australia.

The year’s third partial solar eclipse follows 2018’s second total lunar eclipse and also closes the year’s eclipse lineup. The third partial solar eclipse occurs Saturday, Aug. 11, as a Northern Hemisphere event especially favoring the Arctic Circle.

As the first 2018 eclipse, the blue moon total lunar eclipse Wednesday, Jan. 31, stands out as an eclipse favoring both Southern and Northern Hemispheres and especially as a lunar eclipse coinciding with a blue moon.

Earth as viewed from the center of the moon during Jan. 31, 2018’s blue moon total lunar eclipse’s greatest eclipse: Tom Ruen (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:

graphics and details of blue moon total lunar eclipse Wednesday, Jan. 31, 2018: "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/LEplot/LEplot2001/LE2018Jan31T.pdf

Earth as viewed from the center of the moon during Jan. 31, 2018’s blue moon total lunar eclipse’s greatest eclipse: Tom Ruen (SockPuppetForTomruen at English Wikipedia), Public Domain, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:Lunar_eclipse_from_moon-2018Jan31.png

For further information:

Emspak, Jesse. “Lunar Eclipse 2018 Guide: When, Where & How to See It.” Space.com. Skywatching. Dec. 31, 2017.
Available @ https://www.space.com/33786-lunar-eclipse-guide.html

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

Espenak, Fred. “Key to Lunar Eclipse Global Maps.” NASA Eclipse Web Site > Lunar Eclipses.
Available @ https://eclipse.gsfc.nasa.gov/LEhistory/LEplotkey.html

Espenak, Fred. “Total Lunar Eclipse of 2018 Jan 31.” EclipseWise > Lunar Eclipses > Lunar Eclipses 2001-2100.
Available @ http://eclipsewise.com/lunar/LEprime/2001-2100/LE2018Jan31Tprime.html

Espenak, Fred. “Total Lunar Eclipse of 2018 Jan 31.” NASA Eclipse Web Site > Lunar Eclipses > Lunar Eclipses: 2011-2020.
Available @ https://eclipse.gsfc.nasa.gov/LEplot/LEplot2001/LE2018Jan31T.pdf

Espenak, Fred. “Total Lunar Eclipse of January 31.” EclipseWise > Lunar Eclipses > Eclipses During 2018.
Available @ https://www.eclipsewise.com/oh/ec2018.html

“January 31, 2018 -- Total Lunar Eclipse.” TimeAndDate > Sun & Moon > Eclipses.
Available @ https://www.timeanddate.com/eclipse/lunar/2018-january-31

Marriner, Derdriu. “Blue Moon Month January 2018 Opens New Year 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

Marriner, Derdriu. “Crater Timings for Jan. 31, 2018, Total Lunar Eclipse Show Umbral Span.” Earth and Space News. Wednesday, Jan. 17, 2018.
Available @ https://earth-and-space-news.blogspot.com/2018/01/crater-timings-for-jan-31-2018-total.html

Marriner, Derdriu. “Jan. 31, 2018, Blue Moon Total Lunar Eclipse Belongs to Saros Cycle 124.” Earth and Space News. Wednesday, Jan. 10, 2018.
Available @ https://earth-and-space-news.blogspot.com/2018/01/jan-31-2018-blue-moon-total-lunar.html

McClure, Bruce. “Super Blue Moon Eclipse on January 31.” EarthSky > Tonight. Jan. 30, 2018.
Available @ http://earthsky.org/?p=270280

Rao, Joe. “First Blue Moon Total Lunar Eclipse in 150 Years Coming This Month.” Space.com. Skywatching. Jan. 1, 2018.
Available @ https://www.space.com/39241-first-blue-moon-total-eclipse-150-years.html

Walker, John. “2018 Jan 31 13:29 UTC.” Fourmilab > Earth and Moon Viewer.
Available @ http://www.fourmilab.ch/cgi-bin/Earth

Crater Timings for Jan. 31, 2018, Total Lunar Eclipse Show Umbral Span

Summary: Crater timings for the Jan. 31, 2018, total lunar eclipse show the umbral span by besting limb contacts in predicting Earth's variably sized shadow.

Langrenus Crater in the eastern sector of the moon's Southern Hemisphere is the site of Fred Espenak's final crater timing for the Jan. 31, 2018, total lunar eclipse: Langrenus Crater viewed Dec. 24, 1968, from an altitude of 150 nautical miles by Apollo 8, the first manned mission to the moon: NASA/Apollo 8, Public Domain, via Wikimedia Commons

Crater timings for the Jan. 31, 2018, total lunar eclipse show the umbral span more accurately than suggested lunar limb, or edge, contacts by yielding careful predictions of Earth’s variably sized ecliptic shadow.

Retired NASA astrophysicist Fred Espenak, known as “Mr. Eclipse,” credits Philippe de La Hire (March 18, 1640-April 21, 1718) with discerning that Earth’s umbra displays variably-sized enlargements from one eclipse to the next. In 1702, the French astronomer and mathematician discovered that enlarging the umbra’s radius by one arc minute more than deemed by geometric considerations increases the accuracy of predicted durations of lunar eclipses. One arc minute equals one-sixtieth (1/60) of one degree. One degree represents one-three hundred sixtieth (1/360) of a turn, or full circle.

Earth’s atmosphere influences the umbral enlargement. The process, however, eludes complete understanding as the reason for seemingly variably-sized lunar eclipses remains a mystery.

Careful timings of prominent lunar craters during entrances, termed immersions, into and exits, termed emersions, from the umbra provide clear measurements of a lunar eclipse’s umbral enlargement and yield closely accurate duration predictions for the eclipse’s partiality and totality.

Espenak provides shadow contact timings for lunar eclipses on his dedicated lunar and solar eclipse website, EclipseWise. His table of crater immersion and emersion times for the Wednesday, Jan. 31, 2018, total lunar eclipse tracks umbral contacts with 25 well-defined lunar craters. His predictions for the blue moon total lunar eclipse assumes an approximate atmospherically-induced umbral enlargement of one percent.

Espenak’s calculations begin with Riccioli Crater, located near the western limb in the moon’s Southern Hemisphere. Immersion, or entrance, happens at 11:54 UT. His calculations end with Langrenus, located near the eastern lunar limb in the Southern Hemisphere. Emersion, or exit, happens at 15:05 UT.

The list’s 25 prominent lunar craters are scattered across the western and eastern sectors of both the Northern and Southern Hemispheres of the moon’s near side. Southwestern umbral contact timings comprise five craters:
Billy: 12:03 UT immersion, 14:12 UT emersion;
Campanus: 12:16 UT immersion, 14:22 UT emersion;
Grimaldi: 11:55 UT immersion, 14:12 UT emersion;
Riccioli: 11:54 UT immersion, 14:12 UT emersion;
Tycho: 12:29 UT immersion, 14:26 emersion.

Southeastern umbral contact timings comprise four craters:
Censorinus: 12:32 UT immersion, 14:56 UT emersion;
Goclenius: 12:39 UT immersion, 15:00 UT emersion;
Langrenus: 12:43 UT immersion, 15:05 UT emersion;
Messier: 12:38 UT immersion, 15:02 UT emersion.

Northwestern umbral contact timings consider six craters:
Aristarchus: 11:54 UT immersion, 14:23 UT emersion;
Copernicus: 12:06 UT immersion, 14:32 UT emersion;
Kepler: 11:59 UT immersion, 14:23 UT emersion;
Plato: 12:06 UT immersion, 14:41 UT emersion;
Pytheas: 12:04 UT immersion, 14:33 UT emersion;
Timocharis: 12:06 UT immersion, 14:37 UT emersion.

Northeastern umbral contact timings comprise 10 craters:
Aristoteles: 12:14 UT immersion, 14:49 UT emersion;
Autolycus: 12:11 UT immersion, 14:44 UT emersion;
Dionysius: 12:24 UT immersion, 14:49 UT emersion;
Endymion: 12:23 UT immersion, 14:58 UT emersion;
Eudoxus: 12:15 UT immersion, 14:50 UT emersion;
Manilius: 12:18 UT immersion, 14:47 UT emersion;
Menelaus: 12:20 UT immersion, 14:50 UT emersion;
Plinius: 12:24 UT immersion, 14:54 UT emersion;
Proclus: 12:33 UT immersion, 15:03 UT emersion;
Taruntius: 12:36 UT immersion, 15:03 UT emersion.

Espenak’s summary of the Jan. 31 eclipse suggests times of the event’s major phases based upon lunar limb, or edge, contacts with Earth’s penumbra, or light, outer shadow, and umbra, or dark, inner shadow. Lunar limb contact calculations place the penumbral phase from 10:51:13 Universal Time (UT) to 16:08:32 UT. Partiality begins at 11:48:28 UT and ends at 15:11:14 UT. Totality spans 1 hour 16 minutes 8 seconds, from 12:51:49 to 14:7:57 UT.

Amateur, expert and novice skygazers can record their own timings with two simple tools: a low-power telescope and a watch synchronized with radio time signals. Espenak suggests aiming for a precision of 0.1 minute (six seconds) in timings.

The total lunar eclipse Wednesday, Jan. 31, 2018, occurs as the month’s blue moon. January opens with a full moon, reaching fullness on the month’s second day, and closes with a full moon. In a month with two full moons, the second is designated as a blue moon.

The takeaway for crater timings for the Jan. 31, 2018, total lunar eclipse, which occurs during the month’s blue moon, is that the activity encourages familiarity with lunar features and yields more accurate predictions of eclipse durations.

map of lunar features between 45 north and south latitudes, with Riccioli Crater (site of Fred Espenak's first crater immersion timing) highlighted in blue and Langrenus Crater (site of Fred Espenak's final crater emersion timing) in green: The Defense Mapping Agency Aerospace Center for National Aeronautics and Space Administration (NASA), Public Domain, via NASA Headquarters

Acknowledgment

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

Image credits:

Langrenus Crater in the eastern sector of the moon's Southern Hemisphere is the site of Fred Espenak's final crater timing for the Jan. 31, 2018, total lunar eclipse: Langrenus Crater viewed Dec. 24, 1968, from an altitude of 150 nautical miles by Apollo 8, the first manned mission to the moon: NASA/Apollo 8, Public Domain, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:Langrenus_crater_as08-16-2616hr.jpg

map of lunar features between 45 north and south latitudes, with Langrenus Crater highlighted in green and Riccioli Crater highlighted in blue: The Defense Mapping Agency Aerospace Center for National Aeronautics and Space Administration (NASA), Public Domain, via NASA Headquarters @ https://www.hq.nasa.gov/alsj/NASALunarChart.jpg

For further information:

Espenak, Fred. "Crater Timings During Lunar Eclipses." EclipseWise > Lunar Eclipses > Eclipses During 2018 > Total Lunar Eclipse of January 31
Available @ https://eclipsewise.com/oh/oh-help/LEcrater.html

Espenak, Fred. "Table 1: Total Lunar Eclipse of 2018 Jan 31 Crater Immersion and Emersion Times." EclipseWise > Lunar Eclipses > Eclipses During 2018 > Total Lunar Eclipse of January 31.
Available @ https://eclipsewise.com/oh/oh-tables/ec2018-Tab01.pdf

Espenak, Fred. "Total Lunar Eclipse of January 31." EclipseWise > Lunar Eclipses > Eclipses During 2018.
Available @ https://eclipsewise.com/oh/ec2018.html#LE2018Jan31T

La Hire, Philippe de. Tabulae Astronomicae Ludovici Magni Jussu et Munificentia Exaratæ et In Lucem Editæ: In Quibus Solis, Lunæ Reliquorumque Planetarum Motus ex Ipsis Observationibus, Nulla Adhibita Hypothesi, Traduntur; Habenturque Praecipuarum Fixarum in Nostro Horizonte Conspicuarum Positiones; Ineundi Calculi Methos, cum Geometrica Ratione Computandum Eclipsum Sola Triangulorum Rectilineorum Analysi, Breviter Exponitur; Adjecta Svnt Descriptio, Constructio & Vsus Instrumentorum Astronomiae Novae Practicæ Inservientium, Variaque Problemata Astronomis Geographisque Perutilia. Ad Meridianum Observatorii Regii Parisiensis in Quo Habitae Sunt Observationes ab Ipso Autore. Parisiis [Paris, France]: Joannem Boudot [Jean Boudot], M.DCC.II [1702].
Available via HathiTrust @ https://hdl.handle.net/2027/mdp.39015011942300

Marriner, Derdriu. "Blue Moon Month January 2018 Opens New Year 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

Marriner, Derdriu. "Jan. 31, 2018, Blue Moon Total Lunar Eclipse Belongs to Saros Cycle 124." Earth and Space News. Wednesday, Jan. 10, 2018.
Available @ https://earth-and-space-news.blogspot.com/2018/01/jan-31-2018-blue-moon-total-lunar.html

NASA Aeronautics and Space Administration. Lunar Chart. NASA Headquarters > Apollo Lunar Surface Journal.
Available @ https://www.hq.nasa.gov/alsj/NASALunarChart.jpg

Sinnott, Roger W. "Useful Projects for a Lunar Eclipse." Sky and Telescope > Astronomy News > Observing News. Feb. 19, 2008.
Available @ http://www.skyandtelescope.com/astronomy-news/observing-news/useful-projects-for-a-lunar-eclipse/

Blue Moon Month January 2018 Opens New Year With Two Full Moons

Summary: Blue moon month January 2018 opens the new year with two full moons in the same month, with the second appearance known as blue.

Blue moon month January 2018 showcases two full moons that are supermoons, with the first rating as 2018's closest full moon and the second bestowing blueness upon the month and participating in 2018's first eclipse: Caribe Devine @CaribeDevine, via Twitter July 30, 2015

Blue moon month January 2018 opens the 18th new year of the 21st century with two full moons in the same month and derives blue moon status from the second full occurrence.

Two definitions of blue moon exist. A calendrical definition calls for the occurrence of two full moons within the same month. A seasonal definition identifies the third of four full moons within a single season of three months as a blue moon. January 2018’s second full moon owes its blueness to the calendrical definition.

The first full moon in blue moon month January 2018 reaches fullness Tuesday, Jan. 2, at 2:24 a.m. Coordinated Universal Time (UTC). For North America, fullness occurs Monday, Jan. 1. Variations in dates and times of fullness reflect Earth’s time zones. In reality, fullness takes place at the same instant everywhere.

The second full moon in January 2018 accords blue moon month status to the new year’s first month. January 2018’s blue moon marks entry into fullness Wednesday, Jan. 31, at 13:27 p.m. UTC. (8:27 a.m. Eastern Standard Time; 6:27 a.m. Pacific Standard Time).

Each of the two full moons in blue moon month January 2018 stands out with unique contributions, beyond blue moon month January 2018, to the new year. The Jan. 1-2 full moon claims status as the first full moon of the new year as well as of the new year’s opening month.

The first full moon of blue moon month January 2018 also is recognized as 2018’s closest full moon. The Jan. 1-2 full moon marks a center-to-center distance with Earth of 356,846 kilometers. Turning full only 4.5 hours after the new year’s maximum lunar perigee accounts for the Jan. 1-2 full moon’s status as 2018’s closest full moon.

Lunar perigee (Ancient Greek: περί, perí, “near” + γῆ, gê, “Earth”) signifies the closest center-to-center distance between Earth and moon. Astronomers note lunar perigee for each month as well as for each year. The closest center-to-center distance between Earth and moon occurs Monday, Jan. 1, at 21:54 p.m. UTC (4:54 p.m. EST; 1:54 p.m. PST).

Although the first full moon of blue moon month January 2018 shines as 2018’s closest full moon, the month’s second full moon shares in supermoon status. Credit for coining the term supermoon goes to astrologer Richard Nolle’s article in the October/November 2007 issue of the Mountain Astrologer. EarthSky lead writer Bruce McClure explains Nolle’s term as encompassing any new moon or full moon that has a center-to-center distance with Earth of less than 362,000 kilometers.

January 2018’s blue moon exceeds the month’s first full moon super closeness of 356,846 kilometers by 3,353 kilometers. The month’s second full moon registers a center-to-center distance of 360,199 kilometers.

Blue moon month January 2018’s two full moons participate in a trio of three successive full moon supermoons. The first full moon supermoon in the trio happened Sunday, Dec. 3, 2017, at 15:47 UTC. December 2017’s full moon supermoon logged a center-to-center distance of 357,987 kilometers.

The second full moon of blue moon month January 2018 opens the year’s eclipse lineup of two total lunar and two partial solar eclipses. January 2018’s blue moon rates as marking the year’s first eclipse and also the year’s first lunar eclipse. The new year’s first eclipse begins Wednesday, Jan. 31, at 11:48 a.m. UTC (3:48 a.m. PST).

January 2018’s lunar eclipse begins while the moon is transitioning from its waxing gibbous phase into its full phase. Passage of the moon through Earth’s shadow precedes fullness by 1 hour 39 minutes.

Fullness, however, precedes greatest eclipse by three minutes. Greatest eclipse happens at 13:30 p.m. UTC (5:30 a.m. PST). Greatest eclipse references the instant of the moon’s closest passage with the axis of Earth’s shadow.

The takeaway for blue moon month January 2018 is the spectacle of lunar events happening within the new year’s first month. Two full moon supermoons increase their appeal with proximity to the new year’s closest lunar perigee as a month opener and with participation in a total lunar eclipse as a month closer.

Blue moon month January 2018 features two full moon supermoons that complete a trio of full moon supermoons initiated by 2017's solitary supermoon: Joanne Feldman FOX 5 @JoanneFOX5, via Twitter. Dec. 4, 2017

Acknowledgment

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

Image credits:

"Friday's Blue Moon! Last time it happened: Aug 2012. Next blue moon: Jan 2018 #12news.": Caribe Devine @CaribeDevine, via Twitter July 30, 2015, @ https://twitter.com/CaribeDevine/status/626912015387262976

"A real treat to start 2018! The January 31st full moon is not only a "supermoon", but also a "blue moon" (2nd full moon in the same month)!": Joanne Feldman FOX 5 @JoanneFOX5, via Twitter Dec. 4, 2017, @ https://twitter.com/JoanneFOX5/status/937665428129828866

For further information:

Caribe Devine‏ @CaribeDevine. "Friday's Blue Moon! Last time it happened: Aug 2012. Next blue moon: Jan 2018 #12news." Twitter. July 30, 2015.
Available @ https://twitter.com/CaribeDevine/status/626912015387262976

Espenak, Fred. “2018 Phases of the Moon Eastern Standard Time.” AstroPixels > Ephemeris > Moon > Phases of the Moon From 2001 to 2100.
Available @ http://astropixels.com/ephemeris/astrocal/astrocal2018est.html

Espenak, Fred. "Enlargement of Earth's Shadow." NASA Eclipse Web Site > Lunar Eclipses > Special Interest.
Available @ https://eclipse.gsfc.nasa.gov/LEcat5/shadow.html

Espenak, Fred. “Moon at Perigee and Apogee: 2001 to 2100.” AstroPixels > Ephemeris > Moon > Perigee and Apogee.
Available @ http://astropixels.com/ephemeris/moon/moonperap2001.html

Espenak, Fred. “Total Lunar Eclipse of 2018 Jan 31.” NASA Eclipse Web Site > Lunar Eclipse Page > Lunar Eclipses 2011 – 2020.
Available @ https://eclipse.gsfc.nasa.gov/LEplot/LEplot2001/LE2018Jan31T.pdf

Hiscock, Philip. “Once in a Blue Moon.” Sky & Telescope > Observing > Types of Objects to Observe. Aug. 24, 2012.
Available @ http://www.skyandtelescope.com/observing/celestial-objects-to-watch/once-in-a-blue-moon/

“January 31, 2018 -- Total Lunar Eclipse.” Time And Date > Sun & Moon > Eclipses. <br />
Available @ https://www.timeanddate.com/eclipse/lunar/2018-january-31

Joanne Feldman FOX 5‏ @JoanneFOX5. "A real treat to start 2018! The January 31st full moon is not only a "supermoon", but also a "blue moon" (2nd full moon in the same month)!" Twitter. Dec. 4, 2017.
Available @ https://twitter.com/JoanneFOX5/status/937665428129828866

Lafleur, Laurence J. Question-and-Answer Column. Sky and Telescope. July 1943: 17.
Available via Shop at Sky @ https://www.shopatsky.com/sky-telescope-july-1943-digital-issue

Marriner, Derdriu. "Blue Moon Month July 2015 Ends With Golden Full Moon and Meteor Shower." Earth and Space News. Thursday, July 30, 2015.
Available @ https://earth-and-space-news.blogspot.com/2015/07/blue-moon-month-july-2015-ends-with.html

Marriner, Derdriu. "Blue Moon Month July 2015 Opens With Full Moon Red From Wildfire Smoke." Earth and Space News. Monday, July 6, 2015.
Available @ https://earth-and-space-news.blogspot.com/2015/07/blue-moon-month-july-2015-opens-with.html

McClure, Bruce. “Supermoon on December 3.” EarthSky > Tonight. Dec. 3, 2017.
Available @ http://earthsky.org/tonight/full-supermoon-on-december-3

McClure, Bruce, and Deborah Byrd. “When Is the Next Blue Moon?” EarthSky > Astronomy Essentials. Dec. 1, 2017.
Available @ http://earthsky.org/astronomy-essentials/when-is-the-next-blue-moon

McClure, Bruce, and Deborah Byrd. “When Is the Next Supermoon?” EarthSky > Human World / Space. Dec. 4, 2017.
Available @ http://earthsky.org/space/what-is-a-supermoon

Nolle, Richard. “The SuperMoon and Other Lunar Extremes.” The Mountain Astrologer (Oct/Nov 2007): 20-24.
Available @ http://www.mountainastrologer.com/oldfiles/Nolle1007.html

Nolle, Richard. “Supermoon: What It Is, What It Means.” Astropro > Features > Articles. Last updated March 22, 2011.
Available @ http://www.astropro.com/features/articles/supermoon/

Olson, Donald W., Richard Tresch Fienberg and Roger Sinnott. “What Is a Blue Moon?” Sky & Telescope > Observing > Types of Objects to Observe. July 27, 2006.
Available @ http://www.skyandtelescope.com/observing/celestial-objects-to-watch/what-is-a-blue-moon/

Pruett, James Hugh. “Once in a Blue Moon.” Sky and Telescope. March 1946: 3.
Available via Shop at Sky @ https://www.shopatsky.com/sky-and-telescope-march-1946-digital-issue