A total lunar eclipse occurred at the Moon’s ascending node of orbit on Wednesday, January 31, 2018, with an umbral magnitude of 1.3155. A lunar eclipse occurs when the Moon moves into the Earth's shadow, causing the Moon to be darkened. A total lunar eclipse occurs when the Moon's near side entirely passes into the Earth's umbral shadow. Unlike a solar eclipse, which can only be viewed from a relatively small area of the world, a lunar eclipse may be viewed from anywhere on the night side of Earth. A total lunar eclipse can last up to nearly two hours, while a total solar eclipse lasts only a few minutes at any given place, because the Moon's shadow is smaller. Occurring about 1.4 days after perigee (on January 30, 2018, at 4:55 UTC), the Moon's apparent diameter was larger.

Because the Moon was near its perigee on January 30, it may be described as a "supermoon", when the Moon's distance from the Earth is less than 360,000 km (223,694 miles). The previous supermoon lunar eclipse was on September 28, 2015. The Moon was 360,202 km (223,819 mi) from the Earth. This eclipse also coincided with a blue moon, which occurs when there are two full moons in the same calendar month, or if there are four full moons in the same season (third of four is blue moon). As this supermoon was also a blue moon (the second full moon in a calendar month), it was referred to as a "super blue blood moon"; "blood" refers to the typical red color of the Moon during a total lunar eclipse. This event was called a 'Trifecta'. This coincidence last occurred on December 30, 1982 for the Eastern Hemisphere,Blue moon, based on the previous full moon, was either on November 30 or December 1, 1982, based on time zones. and otherwise before that on March 31, 1866.Rare 'Super Blue Blood Moon' Coming—First in 35 Years, National Geographic, January 29, 2018 The next occurrence will be on January 31, 2037, one metonic cycle (19 years) later.

Background

A lunar eclipse occurs when the Moon passes within Earth's umbra (shadow). As the eclipse begins, Earth's shadow first darkens the Moon slightly. Then, the shadow begins to "cover" part of the Moon, turning it a dark red-brown color (typically – the color can vary based on atmospheric conditions). The Moon appears to be reddish because of Rayleigh scattering (the same effect that causes sunsets to appear reddish) and the refraction of that light by Earth's atmosphere into its umbra.

The following simulation shows the approximate appearance of the Moon passing through Earth's shadow. The northern portion of the Moon is closest to the center of the shadow, making it darkest and reddest in appearance.

"Super blue blood moon" This was a "supermoon", as the Moon was near to its closest distance to earth in its elliptical orbit, making it 7% larger in apparent diameter or 14% larger in area, than an average full moon. The previous supermoon lunar eclipse was during the September 2015 lunar eclipse.Super Blue Moon eclipse on January 31, Earthsky.org, January 30, 2018

The full moon of January 31, 2018 was the second full moon that calendar month (in most time zones), making it, under one definition of the term, a "blue moon".

Additionally referencing the orange or red "blood" colors that occur during a lunar eclipse, media sources described the event as a "super blue blood Moon".

Characteristics Visibility The Pacific Ocean was turned toward the Moon at the time of the eclipse. Central and eastern Asia (including most of Siberia), Philippines, Indonesia, New Zealand and most of Australia got a good view of this moon show in the evening sky. For Western Asia, the Indian subcontinent, the Middle East and Eastern Europe, the eclipse was underway as the moon rose.

Along the U.S. West Coast, the total phase began at 4:51 a.m. PST. The further east, the closer the start of the partial phases coincided with moonset. Along the U.S. Atlantic Seaboard, for instance, the Moon had only just begun to enter the darkest part of Earth's shadow, the umbra, at 6:48 a.m. EST when it disappeared from view below the west-northwest horizon. The duration of the total phase was 77 minutes, with the Moon tracking through the southern part of the Earth's shadow. During totality, the Moon's lower limb appeared brighter than the dark upper limb.

Visibility map

Timing +Event timing by time zoneEclipseHSTAKSTPSTMSTCSTESTUTCMSKISTICTCSTJSTAEDTNZDTZone from UTC −10 h −9 h −8 h −7 h −6 h −5 h 0 h +3 h +5½ h +7 h +8 h +9 h +11 h +13 hPenumbral eclipse begins00:5101:5102:5103:5104:5105:5110:5113:51 —17:5118:5119:5121:5123:51Partial eclipse begins01:4802:4803:4804:4805:4806:4811:4814:4817:1818:4819:4820:4822:4800:48Total eclipse begins02:5203:5204:5205:5206:52 —12:5215:5218:2219:5220:5221:5223:5201:52Mid-eclipse03:3004:3005:3006:30 — —13:3016:3019:0020:3021:3022:3000:3002:30Total eclipse ends04:0805:0806:0807:08 — —14:0817:0819:3821:0822:0823:0801:0803:08Partial eclipse ends05:1106:1107:11 — — —15:1118:1120:4122:1123:1100:1102:1104:11Penumbral eclipse ends06:0807:08 — — — —16:0819:0821:3823:0800:0801:0803:0805:08

Gallery North America

Asia and Middle East

Oceania

Eclipse details Shown below is a table displaying details about this particular lunar eclipse. It describes various parameters pertaining to this eclipse.

+January 31, 2018 Lunar Eclipse Parameters Parameter Value Penumbral Magnitude 2.29538 Umbral Magnitude 1.31671 Gamma −0.30143 Sun Right Ascension 20h56m18.8s Sun Declination -17°17'47.0" Sun Semi-Diameter 16'14.0" Sun Equatorial Horizontal Parallax 08.9" Moon Right Ascension 08h56m05.0s Moon Declination +16°59'44.2" Moon Semi-Diameter 16'35.2" Moon Equatorial Horizontal Parallax 1°00'52.6" ΔT 68.8 s

Eclipse season

This eclipse is part of an eclipse season, a period, roughly every six months, when eclipses occur. Only two (or occasionally three) eclipse seasons occur each year, and each season lasts about 35 days and repeats just short of six months (173 days) later; thus two full eclipse seasons always occur each year. Either two or three eclipses happen each eclipse season. In the sequence below, each eclipse is separated by a fortnight.

+ Eclipse season of January–February 2018 January 31Ascending node (full moon) February 15Descending node (new moon) Total lunar eclipseLunar Saros 124 Partial solar eclipseSolar Saros 150

Related eclipses Eclipses in 2018 A total lunar eclipse on January 31. A partial solar eclipse on February 15. A partial solar eclipse on July 13. A total lunar eclipse on July 27. A partial solar eclipse on August 11.

Metonic Preceded by: Lunar eclipse of April 15, 2014 Followed by: Lunar eclipse of November 19, 2021

Tzolkinex Preceded by: Lunar eclipse of December 21, 2010 Followed by: Lunar eclipse of March 14, 2025

Half-Saros Preceded by: Solar eclipse of January 26, 2009 Followed by: Solar eclipse of February 6, 2027

Tritos Preceded by: Lunar eclipse of March 3, 2007 Followed by: Lunar eclipse of December 31, 2028

Lunar Saros 124 Preceded by: Lunar eclipse of January 21, 2000 Followed by: Lunar eclipse of February 11, 2036

Inex Preceded by: Lunar eclipse of February 20, 1989 Followed by: Lunar eclipse of January 12, 2047

Triad Preceded by: Lunar eclipse of April 2, 1931 Followed by: Lunar eclipse of December 2, 2104

Lunar eclipses of 2016–2020

Saros 124

Tritos series

Inex series

Half-Saros cycle A lunar eclipse will be preceded and followed by solar eclipses by 9 years and 5.5 days (a half saros).Mathematical Astronomy Morsels, Jean Meeus, p.110, Chapter 18, The half-saros This lunar eclipse is related to two annular solar eclipses of Solar Saros 131. January 26, 2009February 6, 2027

See also List of lunar eclipses List of 21st-century lunar eclipses

References

External links

Hermit eclipse: 2018-01-31 LunarEclipse2018.org