June 1973 lunar eclipse

June 1973 lunar eclipse

Penumbral eclipse
The Moon's hourly motion shown right to left
Date	June 15, 1973
Gamma	−1.3217
Magnitude	−0.6020
Saros cycle	110 (69 of 72)
Penumbral	204 minutes, 36 seconds
Contacts (UTC) P1 19:07:39 Greatest 20:49:57 P4 22:32:15
← January 1973 July 1973 →

A penumbral lunar eclipse occurred at the Moon’s ascending node of orbit on Friday, June 15, 1973,^[1] with an umbral magnitude of −0.6020. A lunar eclipse occurs when the Moon moves into the Earth's shadow, causing the Moon to be darkened. A penumbral lunar eclipse occurs when part or all of the Moon's near side passes into the Earth's penumbra. 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. Occurring only about 3 hours after apogee (on June 15, 1973, at 18:05 UTC), the Moon's apparent diameter was smaller.^[2]

This eclipse was the second of four lunar eclipses in 1973, with the others occurring on January 18 (penumbral), July 15 (penumbral), and December 10 (partial).

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

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

June 15, 1973 Lunar Eclipse Parameters

Parameter	Value
Penumbral Magnitude	0.46852
Umbral Magnitude	−0.60197
Gamma	−1.32166
Sun Right Ascension	05h36m24.5s
Sun Declination	+23°19'56.0"
Sun Semi-Diameter	15'44.6"
Sun Equatorial Horizontal Parallax	08.7"
Moon Right Ascension	17h36m42.3s
Moon Declination	-24°31'09.1"
Moon Semi-Diameter	14'42.4"
Moon Equatorial Horizontal Parallax	0°53'58.5"
ΔT	43.8 s

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 June–July 1973

June 15 Ascending node (full moon)	June 30 Descending node (new moon)	July 15 Ascending node (full moon)
Penumbral lunar eclipse Lunar Saros 110	Total solar eclipse Solar Saros 136	Penumbral lunar eclipse Lunar Saros 148

• An annular solar eclipse on January 4.
• A penumbral lunar eclipse on January 18.
• A penumbral lunar eclipse on June 15.
• A total solar eclipse on June 30.
• A penumbral lunar eclipse on July 15.
• A partial lunar eclipse on December 10.
• An annular solar eclipse on December 24.

• Preceded by: Lunar eclipse of August 27, 1969
• Followed by: Lunar eclipse of April 4, 1977

• Preceded by: Lunar eclipse of May 4, 1966
• Followed by: Lunar eclipse of July 27, 1980

• Preceded by: Solar eclipse of June 10, 1964
• Followed by: Solar eclipse of June 21, 1982

• Preceded by: Lunar eclipse of July 17, 1962
• Followed by: Lunar eclipse of May 15, 1984

• Preceded by: Lunar eclipse of June 5, 1955
• Followed by: Lunar eclipse of June 27, 1991

• Preceded by: Lunar eclipse of July 6, 1944
• Followed by: Lunar eclipse of May 26, 2002

• Preceded by: Lunar eclipse of August 14, 1886
• Followed by: Lunar eclipse of April 15, 2060

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 eclipses on January 18, 1973 and July 15, 1973 occur in the previous lunar year eclipse set.

Lunar eclipse series sets from 1973 to 1976
Ascending node					Descending node
Saros	Date Viewing	Type Chart	Gamma		Saros	Date Viewing	Type Chart	Gamma
110	1973 Jun 15	Penumbral	−1.3217		115	1973 Dec 10	Partial	0.9644
120	1974 Jun 04	Partial	−0.5489		125	1974 Nov 29	Total	0.3054
130	1975 May 25	Total	0.2367		135	1975 Nov 18	Total	−0.4134
140	1976 May 13	Partial	0.9586		145	1976 Nov 06	Penumbral	−1.1276

This eclipse is a part of Saros series 110, repeating every 18 years, 11 days, and containing 72 events. The series started with a penumbral lunar eclipse on May 28, 747 AD. It contains partial eclipses from August 23, 891 AD through April 18, 1288; total eclipses from April 29, 1306 through September 5, 1522; and a second set of partial eclipses from September 16, 1540 through April 22, 1883. The series ends at member 72 as a penumbral eclipse on July 18, 2027.

The longest duration of totality was produced by member 38 at 103 minutes, 8 seconds on July 3, 1414. All eclipses in this series occur at the Moon’s ascending node of orbit.^[6]

Greatest	First
The greatest eclipse of the series occurred on 1414 Jul 03, lasting 103 minutes, 8 seconds.[7]	Penumbral	Partial	Total	Central
	747 May 28	891 Aug 23	1306 Apr 29	1360 May 31
	Last
	Central	Total	Partial	Penumbral
	1468 Aug 04	1522 Sep 05	1883 Apr 22	2027 Jul 18

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 60–72 occur between 1801 and 2027:
60		61		62
1811 Mar 10		1829 Mar 20		1847 Mar 31
63		64		65
1865 Apr 11		1883 Apr 22		1901 May 03
66		67		68
1919 May 15		1937 May 25		1955 Jun 05
69		70		71
1973 Jun 15		1991 Jun 27		2009 Jul 07
72
2027 Jul 18

A lunar eclipse will be preceded and followed by solar eclipses by 9 years and 5.5 days (a half saros).^[8] This lunar eclipse is related to two partial solar eclipses of Solar Saros 117.

June 10, 1964	June 21, 1982

• List of lunar eclipses
• List of 20th-century lunar eclipses

• 1973 Jun 15 chart Eclipse Predictions by Fred Espenak, NASA/GSFC