en May 2004 lunar eclipse

May 2004 lunar eclipse
Total eclipse
	Totality as viewed from Haifa, Israel
Date	May 4, 2004
Gamma	−0.3132
Magnitude	1.3035
Saros cycle	131 (33 of 72)
Totality	75 minutes, 28 seconds
Partiality	203 minutes, 12 seconds
Penumbral	315 minutes, 43 seconds
P1
Contacts (UTC)
P1	17:52:54
U1	18:48:38
U2	19:52:29
Greatest	20:30:13
U3	21:07:57
U4	22:11:50
P4	23:08:03
	← November 2003 October 2004 →

A total lunar eclipse occurred at the Moon’s descending node of orbit on Tuesday, May 4, 2004,^[1] with an umbral magnitude of 1.3035. 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 1.2 days before perigee (on May 6, 2004, at 0:30 UTC), the Moon's apparent diameter was larger.^[2]

This lunar eclipse is the third of a tetrad, with four total lunar eclipses in series, the others being on May 16, 2003; November 9, 2004; and October 28, 2004.

Visibility

The eclipse was completely visible over much of Africa, eastern Europe, Antarctica, and Asia, central, and south Asia, seen rising over South America, western Europe, and west Africa and setting over east Asia and Australia.^[3]

	Hourly motion shown right to left
The moon's hourly motion across the Earth's shadow in the constellation of Libra.

Eclipse details

Shown below is a table displaying details about this particular solar eclipse. It describes various parameters pertaining to this eclipse.^[4]

May 4, 2004 Lunar Eclipse Parameters
Parameter	Value
Penumbral Magnitude	2.26449
Umbral Magnitude	1.30536
Gamma	−0.31320
Sun Right Ascension	02h48m55.8s
Sun Declination	+16°14'51.5"
Sun Semi-Diameter	15'51.5"
Sun Equatorial Horizontal Parallax	08.7"
Moon Right Ascension	14h48m25.1s
Moon Declination	-16°32'22.6"
Moon Semi-Diameter	16'32.0"
Moon Equatorial Horizontal Parallax	1°00'40.8"
ΔT	64.5 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 April–May 2004
April 19 Ascending node (new moon)	May 4 Descending node (full moon)

Partial solar eclipse Solar Saros 119	Total lunar eclipse Lunar Saros 131

Related lunar eclipses

Eclipses in 2004

Lunar eclipses of 2002–2005

Lunar eclipse series sets from 2002–2005
Descending node				Ascending node
Saros Photo	Date View	Type Chart	Gamma	Saros Photo	Date View	Type Chart	Gamma
111	2002 May 26	penumbral	1.1759	116	2002 Nov 20	penumbral	−1.1127
121	2003 May 16	total	0.4123	126	2003 Nov 09	total	−0.4319
131	2004 May 04	total	−0.3132	136	2004 Oct 28	total	0.2846
141	2005 Apr 24	penumbral	−1.0885	146	2005 Oct 17	partial	0.9796

Last set	2002 Jun 24			Last set	2001 Dec 30

Next set	2006 Mar 14			Next set	2006 Sep 07

Saros 131

Lunar Saros series 131, has 72 lunar eclipses. Solar Saros 138 interleaves with this lunar saros with an event occurring every 9 years 5 days alternating between each saros series.

This eclipse series began in AD 1427 with a partial eclipse at the southern edge of the Earth's shadow when the Moon was close to its descending node. Each successive Saros cycle, the Moon's orbital path is shifted northward with respect to the Earth's shadow, with the first total eclipse occurring in 1950. For the following 252 years, total eclipses occur, with the central eclipse being predicted to occur in 2078. The first partial eclipse after this is predicted to occur in the year 2220, and the final partial eclipse of the series will occur in 2707. The total lifetime of the lunar Saros series 131 is 1280 years. Solar Saros 138 interleaves with this lunar saros with an event occurring every 9 years 5 days alternating between each saros series.

Because of the ⅓ fraction of days in a Saros cycle, the visibility of each eclipse will differ for an observer at a given fixed locale. For the lunar Saros series 131, the first total eclipse of 1950 had its best visibility for viewers in Eastern Europe and the Middle East because mid-eclipse was at 20:44 UT. The following eclipse in the series occurred approximately 8 hours later in the day with mid-eclipse at 4:47 UT, and was best seen from North America and South America. The third total eclipse occurred approximately 8 hours later in the day than the second eclipse with mid-eclipse at 12:43 UT, and had its best visibility for viewers in the Western Pacific, East Asia, Australia and New Zealand. This cycle of visibility repeats from the initiation to termination of the series, with minor variations. Solar Saros 138 interleaves with this lunar saros with an event occurring every 9 years 5 days alternating between each saros series.

Lunar Saros series 131, repeating every 18 years and 11 days, has a total of 72 lunar eclipse events including 57 umbral lunar eclipses (42 partial lunar eclipses and 15 total lunar eclipses). Solar Saros 138 interleaves with this lunar saros with an event occurring every 9 years 5 days alternating between each saros series.

Greatest	First
The greatest eclipse of the series will occur on 2094 Jun 28, lasting 102 minutes.^[5]	Penumbral	Partial	Total	Central
	1427 May 10	1553 July 25	1950 Apr 2	2022 May 16
	Last
	Central	Total	Partial	Penumbral
	2148 Jul 31	2202 Sep 3	2563 Apr 9	2707 Jul 7

Metonic series

The metonic cycle repeats nearly exactly every 19 years and represents a Saros cycle plus one lunar year. Because it occurs on the same calendar date, the Earth's shadow will in nearly the same location relative to the background stars.

Metonic events: May 4 and October 28
Descending node	Ascending node
1966 May 4 - Penumbral (111) 1985 May 4 - Total (121) 2004 May 4 - Total (131) 2023 May 5 - Penumbral (141)	1966 Oct 29 - Penumbral (116) 1985 Oct 28 - Total (126) 2004 Oct 28 - Total (136) 2023 Oct 28 - Partial (146) 2042 Oct 28 - Penumbral (156)

Half-Saros cycle

A lunar eclipse will be preceded and followed by solar eclipses by 9 years and 5.5 days (a half saros).^[6] This lunar eclipse is related to two annular solar eclipses of Solar Saros 138.