| 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 | ||||||||||||||||
| |||||||||||||||||
A totallunar eclipse occurred at the Moon’sdescending node of orbit on Thursday, September 6, 1979,[1] with an umbralmagnitude of 1.0936. A lunar eclipse occurs when theMoon moves into theEarth'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 asolar eclipse, which can only be viewed from a relatively small area of the world, a lunar eclipse may be viewed from anywhere on thenight 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'sshadow is smaller. Occurring only about 5 hours afterperigee (on September 6, 1979, at 6:00 UTC), the Moon's apparent diameter was larger.[2]
The eclipse was completely visible over easternAustralia, westernNorth America, and the central and easternPacific Ocean, seen rising over the eastern half ofAsia and western Australia and setting over North andSouth America.[3]
 |
Shown below is a table displaying details about this particular lunar eclipse. It describes various parameters pertaining to this eclipse.[4]
| 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 |
This eclipse is part of aneclipse 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 afortnight.
| August 22 Ascending node (new moon) | September 6 Descending node (full moon) |
|---|---|
 | |
| Annular solar eclipse Solar Saros 125 | Total lunar eclipse Lunar Saros 137 |
This eclipse is a member of asemester series. An eclipse in a semester series of lunar eclipses repeats approximately every 177 days and 4 hours (a semester) at alternatingnodes of the Moon's orbit.[5]
The penumbral lunar eclipse onJuly 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 | |
This eclipse is a part ofSaros series 137, repeating every 18 years, 11 days, and containing 78 events. The series started with a penumbral lunar eclipse on December 17, 1564. It contains partial eclipses from June 10, 1835 throughAugust 26, 1961; total eclipses fromSeptember 6, 1979 through June 28, 2466; and a second set of partial eclipses from July 9, 2484 through September 12, 2592. The series ends at member 78 as a penumbral eclipse on April 20, 2953.
The longest duration of totality will be produced by member 44 at 99 minutes, 53 seconds on April 13, 2340. All eclipses in this series occur at the Moon’sdescending node of orbit.[6]
| Greatest | First | |||
|---|---|---|---|---|
| The greatest eclipse of the series will occur on2340 Apr 13, lasting 99 minutes, 53 seconds.[7] | Penumbral | Partial | Total | Central |
| 1564 Dec 17 | 1835 Jun 10 | 1979 Sep 06 | 2051 Oct 19 | |
| Last | ||||
| Central | Total | Partial | Penumbral | |
| 2412 May 26 | 2466 Jun 28 | 2592 Sep 12 | 2953 Apr 20 | |
Eclipses are tabulated in three columns; every third eclipse in the same column is oneexeligmos apart, so they all cast shadows over approximately the same parts of the Earth.
| Series members 15–36 occur between 1801 and 2200: | |||||
|---|---|---|---|---|---|
| 15 | 16 | 17 | |||
| 1817 May 30 | 1835 Jun 10 | 1853 Jun 21 | |||
| 18 | 19 | 20 | |||
| 1871 Jul 02 | 1889 Jul 12 | 1907 Jul 25 | |||
 |  | ||||
| 21 | 22 | 23 | |||
| 1925 Aug 04 | 1943 Aug 15 | 1961 Aug 26 | |||
 |  |  |  |  |  |
| 24 | 25 | 26 | |||
| 1979 Sep 06 | 1997 Sep 16 | 2015 Sep 28 | |||
| |  |  |  |  |
| 27 | 28 | 29 | |||
| 2033 Oct 08 | 2051 Oct 19 | 2069 Oct 30 | |||
 |  | |  |  |  |
| 30 | 31 | 32 | |||
| 2087 Nov 10 | 2105 Nov 21 | 2123 Dec 03 | |||
 |  | ||||
| 33 | 34 | 35 | |||
| 2141 Dec 13 | 2159 Dec 24 | 2178 Jan 04 | |||
| 36 | |||||
| 2196 Jan 15 | |||||
This eclipse is a part of atritos cycle, repeating at alternating nodes every 135synodic months (≈ 3986.63 days, or 11 years minus 1 month). Their appearance and longitude are irregular due to a lack of synchronization with theanomalistic 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 2187 | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| 1805 Jan 15 (Saros 121) | 1815 Dec 16 (Saros 122) | 1826 Nov 14 (Saros 123) | 1837 Oct 13 (Saros 124) | 1848 Sep 13 (Saros 125) | |||||
| 1859 Aug 13 (Saros 126) | 1870 Jul 12 (Saros 127) | 1881 Jun 12 (Saros 128) | 1892 May 11 (Saros 129) | 1903 Apr 12 (Saros 130) | |||||
 |  | ||||||||
| 1914 Mar 12 (Saros 131) | 1925 Feb 08 (Saros 132) | 1936 Jan 08 (Saros 133) | 1946 Dec 08 (Saros 134) | 1957 Nov 07 (Saros 135) | |||||
 |  |  |  |  |  |  |  |  |  |
| 1968 Oct 06 (Saros 136) | 1979 Sep 06 (Saros 137) | 1990 Aug 06 (Saros 138) | 2001 Jul 05 (Saros 139) | 2012 Jun 04 (Saros 140) | |||||
 |  | | |  |  |  |  |  |  |
| 2023 May 05 (Saros 141) | 2034 Apr 03 (Saros 142) | 2045 Mar 03 (Saros 143) | 2056 Feb 01 (Saros 144) | 2066 Dec 31 (Saros 145) | |||||
 |  |  |  |  |  |  |  | ||
| 2077 Nov 29 (Saros 146) | 2088 Oct 30 (Saros 147) | 2099 Sep 29 (Saros 148) | 2110 Aug 29 (Saros 149) | 2121 Jul 30 (Saros 150) | |||||
 |  | ||||||||
| 2132 Jun 28 (Saros 151) | 2143 May 28 (Saros 152) | 2154 Apr 28 (Saros 153) | |||||||
| 2187 Jan 24 (Saros 156) | |||||||||
This eclipse is a part of the long periodinex cycle, repeating at alternating nodes, every 358synodic months (≈ 10,571.95 days, or 29 years minus 20 days). Their appearance and longitude are irregular due to a lack of synchronization with theanomalistic 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 | |||||
|---|---|---|---|---|---|
| 1806 Jan 05 (Saros 131) | 1834 Dec 16 (Saros 132) | 1863 Nov 25 (Saros 133) | |||
| 1892 Nov 04 (Saros 134) | 1921 Oct 16 (Saros 135) | 1950 Sep 26 (Saros 136) | |||
 |  |  |  | ||
| 1979 Sep 06 (Saros 137) | 2008 Aug 16 (Saros 138) | 2037 Jul 27 (Saros 139) | |||
| |  |  |  |  |
| 2066 Jul 07 (Saros 140) | 2095 Jun 17 (Saros 141) | 2124 May 28 (Saros 142) | |||
| 2153 May 08 (Saros 143) | 2182 Apr 18 (Saros 144) | ||||
A lunar eclipse will be preceded and followed by solar eclipses by 9 years and 5.5 days (ahalf saros).[8] This lunar eclipse is related to two annular solar eclipses ofSolar Saros 144.
| August 31, 1970 | September 11, 1988 |
|---|---|
 |  |
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