en September 1979 lunar eclipse

September 1979 lunar eclipse
Total eclipse
	The Moon's hourly motion shown right to left
Date	September 6, 1979
Gamma	−0.4305
Magnitude	1.0936
Saros cycle	137 (26 of 81)
Totality	44 minutes, 25 seconds
Partiality	191 minutes, 52 seconds
Penumbral	305 minutes, 9 seconds
P1
Contacts (UTC)
P1	8:21:37
U1	9:18:15
U2	10:31:59
Greatest	10:54:12
U3	11:16:24
U4	12:30:08
P4	13:26:45
	← March 1979 March 1980 →

A total lunar eclipse occurred at the Moon’s descending node of orbit on Thursday, September 6, 1979,^[1] with an umbral magnitude of 1.0936. 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 only about 5 hours after perigee (on September 6, 1979, at 6:00 UTC), the Moon's apparent diameter was larger.^[2]

Visibility

The eclipse was completely visible over eastern Australia, western North America, and the central and eastern Pacific Ocean, seen rising over the eastern half of Asia and western Australia and setting over North and South America.^[3]

Eclipse details

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

September 6, 1979 Lunar Eclipse Parameters
Parameter	Value
Penumbral Magnitude	2.04211
Umbral Magnitude	1.09358
Gamma	−0.43050
Sun Right Ascension	10h58m17.1s
Sun Declination	+06°34'46.5"
Sun Semi-Diameter	15'52.1"
Sun Equatorial Horizontal Parallax	08.7"
Moon Right Ascension	22h58m48.1s
Moon Declination	-07°00'03.6"
Moon Semi-Diameter	16'43.7"
Moon Equatorial Horizontal Parallax	1°01'23.8"
ΔT	50.2 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 August–September 1979
August 22 Ascending node (new moon)	September 6 Descending node (full moon)

Annular solar eclipse Solar Saros 125	Total lunar eclipse Lunar Saros 137

Related eclipses

Lunar eclipses of 1977–1980

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.^[5]

The penumbral lunar eclipse on July 27, 1980 occurs in the next lunar year eclipse set.

Lunar eclipse series sets from 1977 to 1980
Ascending node				Descending node
Saros	Date Viewing	Type Chart	Gamma	Saros	Date Viewing	Type Chart	Gamma
112	1977 Apr 04	Partial	−0.9148	117	1977 Sep 27	Penumbral	1.0768
122	1978 Mar 24	Total	−0.2140	127	1978 Sep 16	Total	0.2951
132	1979 Mar 13	Partial	0.5254	137	1979 Sep 06	Total	−0.4305
142	1980 Mar 01	Penumbral	1.2270	147	1980 Aug 26	Penumbral	−1.1608

Saros 137

It is part of Saros series 137.

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 144.