July 2018 lunar eclipse

A total lunar eclipse occurred at the Moon’s descending node of orbit on Friday, July 27, 2018,^[1] with an umbral magnitude of 1.6100. It was a central lunar eclipse, in which part of the Moon passed through the center of the Earth's shadow. 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 19 hours after apogee (on July 27, 2018, at 1:45 UTC), the Moon's apparent diameter was smaller.^[2]

July 2018 lunar eclipse

Total eclipse
Totality as viewed from Oria, Italy, 21:09 UTC
Date	July 27, 2018
Gamma	0.1168
Magnitude	1.6100
Saros cycle	129 (38 of 71)
Totality	102 minutes, 57 seconds
Partiality	234 minutes, 33 seconds
Penumbral	373 minutes, 48 seconds
Contacts (UTC) P1 17:14:49 U1 18:24:27 U2 19:30:15 Greatest 20:21:44 U3 21:13:12 U4 22:19:00 P4 23:28:37
← January 2018 January 2019 →

This was the first central lunar eclipse since June 15, 2011. It was also the longest total lunar eclipse of the 21st century, but not the longest in the 3rd millennium.^[3] Totality lasted one hour and 42.955 minutes,^[4][5][6][7] a period "just short of the theoretical limit of a lunar eclipse (one hour and 46.605 minutes)".^[8] The Moon remained at least partially in Earth's shadow for three hours 54.55 minutes.^[8] The longest total lunar eclipse of the 3rd millennium will occur on May 12, 2264, lasting 106 minutes and 13.2 seconds, which will be the longest total lunar eclipse since 2000, and the longest one until 3107.

The eclipse occurred when the Moon was near its maximum distance from Earth, which caused the Moon to appear smaller than normal (a phenomenon sometimes called a micromoon),^[9][10] and to travel at its slowest speed in its orbit around Earth.^[3]

This lunar eclipse coincided with Mars being nearly as close as possible to Earth, a concurrence that happens once every 25,000 years.^[6]

Background

Main article: Lunar eclipse

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 Earth's shadow begins to cover part of the Moon, typically turning it a dark red-brown color (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 daytime sky to appear blue) and the refraction of that light by Earth's atmosphere into its umbra.^[11]

The Moon's brightness is exaggerated within the umbral shadow.^[11] The southern portion of the Moon was closest to the center of the shadow, making it the darkest, and most red in appearance.^{[citation needed]}

Animation showing the approximate appearance of the Moon passing through Earth's shadow

Visibility

The eclipse was completely visible over east Africa, southern Africa, south and central Asia, seen rising over South America, west Africa, and Europe, and setting over east Asia and Australia.^[12][13]

Visibility map

Gallery

• 
  Animation of the eclipse from Athens, Greece
• Video of the eclipse from Yekaterinburg, Russia
• 
  Nanjing, China, 18:25 UTC
• 
  Asunción, Paraguay 19:10 UTC
• 
  Rethymnon, Greece 19:14 UTC
• 
  Johannesburg, South Africa, 19:16 UTC
• 
  Guangzhou, China, 19:20 UTC
• 
  Limassol, Cyprus, 19:27 UTC
• 
  Tashkent, Uzbekistan, 19:32 UTC
• 
  Jerusalem, Israel, 19:33 UTC
• 
  Eclipse with Mars, Fukuoka, Japan, 19:46 UTC
• 
  Davao City, Philippines, 19:52 UTC
• 
  Cracow, Poland, 20:05 UTC
• 
  Chelsea, Victoria, Australia, 20:07 UTC
• 
  Maximum from Banjarmasin, Indonesia, 20:21 UTC
• 
  Tuen Mun, Hong Kong, 20:47 UTC
• 
  Huittinen, Finland, 21:05 UTC
• 
  Graz, Austria, 21:12 UTC
• 
  Toulouse, France, 21:17 UTC
• 
  Berlin, Germany, 21:19 UTC
• 
  Torino, Italy, 21:19 UTC
• 
  Hamburg, Germany, 21:23 UTC
• 
  Brastad, Sweden, 21:24 UTC
• 
  León, Spain, 21:27 UTC

Eclipse details

Shown below is a table displaying details about this particular lunar eclipse. It describes various parameters pertaining to this eclipse.^[14]

July 27, 2018 Lunar Eclipse Parameters

Parameter	Value
Penumbral Magnitude	2.68050
Umbral Magnitude	1.60996
Gamma	0.11681
Sun Right Ascension	08h28m22.0s
Sun Declination	+19°04'25.2"
Sun Semi-Diameter	15'45.0"
Sun Equatorial Horizontal Parallax	08.7"
Moon Right Ascension	20h28m18.2s
Moon Declination	-18°58'10.6"
Moon Semi-Diameter	14'42.7"
Moon Equatorial Horizontal Parallax	0°53'59.7"
ΔT	68.9 s

Eclipse season

See also: Eclipse cycle

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. The first and last eclipse in this sequence is separated by one synodic month.

Eclipse season of July–August 2018

July 13 Ascending node (new moon)	July 27 Descending node (full moon)	August 11 Ascending node (new moon)
Partial solar eclipse Solar Saros 117	Total lunar eclipse Lunar Saros 129	Partial solar eclipse Solar Saros 155

Related eclipses

Wide angle view of the total lunar eclipse and Mars in Melbourne, Australia

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 October 8, 2014
• Followed by: Lunar eclipse of May 16, 2022

Tzolkinex

• Preceded by: Lunar eclipse of June 15, 2011
• Followed by: Lunar eclipse of September 7, 2025

Half-Saros

• Preceded by: Solar eclipse of July 22, 2009
• Followed by: Solar eclipse of August 2, 2027

Tritos

• Preceded by: Lunar eclipse of August 28, 2007
• Followed by: Lunar eclipse of June 26, 2029

Lunar Saros 129

• Preceded by: Lunar eclipse of July 16, 2000
• Followed by: Lunar eclipse of August 7, 2036

Inex

• Preceded by: Lunar eclipse of August 17, 1989
• Followed by: Lunar eclipse of July 7, 2047

Triad

• Preceded by: Lunar eclipse of September 26, 1931
• Followed by: Lunar eclipse of May 28, 2105

Lunar eclipses of 2016–2020

This eclipse is a member of a semester series. An eclipse in a semester series of lunar eclipses repeats approximately every 177 days and 4 hours (a semester) at alternating nodes of the Moon's orbit.^[15]

The penumbral lunar eclipses on March 23, 2016 and September 16, 2016 occur in the previous lunar year eclipse set, and the penumbral lunar eclipses on June 5, 2020 and November 30, 2020 occur in the next lunar year eclipse set.

Lunar eclipse series sets from 2016 to 2020
Descending node					Ascending node
Saros	Date Viewing	Type Chart	Gamma		Saros	Date Viewing	Type Chart	Gamma
109	2016 Aug 18	Penumbral	1.5641		114	2017 Feb 11	Penumbral	−1.0255
119	2017 Aug 07	Partial	0.8669		124	2018 Jan 31	Total	−0.3014
129	2018 Jul 27	Total	0.1168		134	2019 Jan 21	Total	0.3684
139	2019 Jul 16	Partial	−0.6430		144	2020 Jan 10	Penumbral	1.0727
149	2020 Jul 05	Penumbral	−1.3639

Saros 129

This eclipse is a part of Saros series 129, repeating every 18 years, 11 days, and containing 71 events. The series started with a penumbral lunar eclipse on June 10, 1351. It contains partial eclipses from September 26, 1531 through May 11, 1892; total eclipses from May 24, 1910 through September 8, 2090; and a second set of partial eclipses from September 20, 2108 through April 26, 2469. The series ends at member 71 as a penumbral eclipse on July 24, 2613.

The longest duration of totality was produced by member 37 at 106 minutes, 24 seconds on July 16, 2000. All eclipses in this series occur at the Moon’s descending node of orbit.^[16]

Greatest	First
The greatest eclipse of the series occurred on 2000 Jul 16, lasting 106 minutes, 24 seconds.[17]	Penumbral	Partial	Total	Central
	1351 Jun 10	1531 Sep 26	1910 May 24	1946 Jun 14
	Last
	Central	Total	Partial	Penumbral
	2036 Aug 07	2090 Sep 08	2469 Apr 26	2613 Jul 24

Eclipses are tabulated in three columns; every third eclipse in the same column is one exeligmos apart, so they all cast shadows over approximately the same parts of the Earth.

Series members 26–48 occur between 1801 and 2200:
26		27		28
1802 Mar 19		1820 Mar 29		1838 Apr 10
29		30		31
1856 Apr 20		1874 May 01		1892 May 11
32		33		34
1910 May 24		1928 Jun 03		1946 Jun 14
35		36		37
1964 Jun 25		1982 Jul 06		2000 Jul 16
38		39		40
2018 Jul 27		2036 Aug 07		2054 Aug 18
41		42		43
2072 Aug 28		2090 Sep 08		2108 Sep 20
44		45		46
2126 Oct 01		2144 Oct 11		2162 Oct 23
47		48
2180 Nov 02		2198 Nov 13

Tritos series

This eclipse is a part of a tritos cycle, repeating at alternating nodes every 135 synodic months (≈ 3986.63 days, or 11 years minus 1 month). Their appearance and longitude are irregular due to a lack of synchronization with the anomalistic month (period of perigee), but groupings of 3 tritos cycles (≈ 33 years minus 3 months) come close (≈ 434.044 anomalistic months), so eclipses are similar in these groupings.

Series members between 1801 and 2200
1811 Mar 10 (Saros 110)		1822 Feb 06 (Saros 111)		1833 Jan 06 (Saros 112)		1843 Dec 07 (Saros 113)		1854 Nov 04 (Saros 114)
1865 Oct 04 (Saros 115)		1876 Sep 03 (Saros 116)		1887 Aug 03 (Saros 117)		1898 Jul 03 (Saros 118)		1909 Jun 04 (Saros 119)
1920 May 03 (Saros 120)		1931 Apr 02 (Saros 121)		1942 Mar 03 (Saros 122)		1953 Jan 29 (Saros 123)		1963 Dec 30 (Saros 124)
1974 Nov 29 (Saros 125)		1985 Oct 28 (Saros 126)		1996 Sep 27 (Saros 127)		2007 Aug 28 (Saros 128)		2018 Jul 27 (Saros 129)
2029 Jun 26 (Saros 130)		2040 May 26 (Saros 131)		2051 Apr 26 (Saros 132)		2062 Mar 25 (Saros 133)		2073 Feb 22 (Saros 134)
2084 Jan 22 (Saros 135)		2094 Dec 21 (Saros 136)		2105 Nov 21 (Saros 137)		2116 Oct 21 (Saros 138)		2127 Sep 20 (Saros 139)
2138 Aug 20 (Saros 140)		2149 Jul 20 (Saros 141)		2160 Jun 18 (Saros 142)		2171 May 19 (Saros 143)		2182 Apr 18 (Saros 144)
2193 Mar 17 (Saros 145)

Inex series

This eclipse is a part of the long period inex cycle, repeating at alternating nodes, every 358 synodic months (≈ 10,571.95 days, or 29 years minus 20 days). Their appearance and longitude are irregular due to a lack of synchronization with the anomalistic month (period of perigee). However, groupings of 3 inex cycles (≈ 87 years minus 2 months) comes close (≈ 1,151.02 anomalistic months), so eclipses are similar in these groupings.

Series members between 1801 and 2200
1815 Dec 16 (Saros 122)		1844 Nov 24 (Saros 123)		1873 Nov 04 (Saros 124)
1902 Oct 17 (Saros 125)		1931 Sep 26 (Saros 126)		1960 Sep 05 (Saros 127)
1989 Aug 17 (Saros 128)		2018 Jul 27 (Saros 129)		2047 Jul 07 (Saros 130)
2076 Jun 17 (Saros 131)		2105 May 28 (Saros 132)		2134 May 08 (Saros 133)
2163 Apr 19 (Saros 134)		2192 Mar 28 (Saros 135)

Half-Saros cycle

A lunar eclipse will be preceded and followed by solar eclipses by 9 years and 5.5 days (a half saros).^[18] This lunar eclipse is related to two total solar eclipses of Solar Saros 136.

July 22, 2009	August 22, 2027

See also

• List of lunar eclipses and List of 21st-century lunar eclipses