| Total eclipse | |||||||||||||||||
 The Moon's hourly motion shown right to left | |||||||||||||||||
| Date | November 18, 1956 | ||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Gamma | 0.2917 | ||||||||||||||||
| Magnitude | 1.3172 | ||||||||||||||||
| Saros cycle | 125 (45 of 72) | ||||||||||||||||
| Totality | 78 minutes, 22 seconds | ||||||||||||||||
| Partiality | 209 minutes, 27 seconds | ||||||||||||||||
| Penumbral | 332 minutes, 13 seconds | ||||||||||||||||
| |||||||||||||||||
A totallunar eclipse occurred at the Moon’sdescending node of orbit on Sunday, November 18, 1956,[1] with an umbralmagnitude of 1.3172. 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 about 3.4 days beforeperigee (on November 21, 1956, at 16:45 UTC), the Moon's apparent diameter was larger.[2]
This lunar eclipse was the second of analmost tetrad, with the others being onMay 24, 1956 (partial);May 13, 1957 (total); andNovember 7, 1957 (total).
The eclipse was completely visible overNorth America and westernSouth America, seen rising overnortheast Asia and easternAustralia and setting over eastern South America,west andcentral Africa, andEurope.[3]
 |
Shown below is a table displaying details about this particular solar eclipse. It describes various parameters pertaining to this eclipse.[4]
| Parameter | Value |
|---|---|
| Penumbral Magnitude | 2.32849 |
| Umbral Magnitude | 1.31720 |
| Gamma | 0.29167 |
| Sun Right Ascension | 15h34m22.3s |
| Sun Declination | -19°14'20.7" |
| Sun Semi-Diameter | 16'11.0" |
| Sun Equatorial Horizontal Parallax | 08.9" |
| Moon Right Ascension | 03h34m12.2s |
| Moon Declination | +19°31'18.5" |
| Moon Semi-Diameter | 16'00.2" |
| Moon Equatorial Horizontal Parallax | 0°58'44.0" |
| ΔT | 31.8 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.
| November 18 Descending node (full moon) | December 2 Ascending node (new moon) |
|---|---|
|  |
| Total lunar eclipse Lunar Saros 125 | Partial solar eclipse Solar Saros 151 |
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 onJanuary 8, 1955 occurs in the previous lunar year eclipse set, and the penumbral lunar eclipse onApril 4, 1958 occurs in the next lunar year eclipse set.
| Lunar eclipse series sets from 1955 to 1958 | ||||||||
|---|---|---|---|---|---|---|---|---|
| Ascending node | Descending node | |||||||
| Saros | Date Viewing | Type Chart | Gamma | Saros | Date Viewing | Type Chart | Gamma | |
| 110 | 1955 Jun 05 | Penumbral | −1.2384 | 115 | 1955 Nov 29 | Partial | 0.9551 | |
| 120 | 1956 May 24 | Partial | −0.4726 | 125 | 1956 Nov 18 | Total | 0.2917 | |
| 130 | 1957 May 13 | Total | 0.3046 | 135 | 1957 Nov 07 | Total | −0.4332 | |
| 140 | 1958 May 03 | Partial | 1.0188 | 145 | 1958 Oct 27 | Penumbral | −1.1571 | |
This eclipse is a part ofSaros series 125, repeating every 18 years, 11 days, and containing 72 events. The series started with a penumbral lunar eclipse on July 17, 1163. It contains partial eclipses from January 17, 1470 through June 6, 1686; total eclipses from June 17, 1704 through March 19, 2155; and a second set of partial eclipses from March 29, 2173 through June 25, 2317. The series ends at member 72 as a penumbral eclipse on September 9, 2443.
The longest duration of totality was produced by member 37 at 100 minutes, 23 seconds on August 22, 1812. All eclipses in this series occur at the Moon’sdescending node of orbit.[6]
| Greatest | First | |||
|---|---|---|---|---|
| The greatest eclipse of the series occurred on1812 Aug 22, lasting 100 minutes, 23 seconds.[7] | Penumbral | Partial | Total | Central |
| 1163 Jul 17 | 1470 Jan 17 | 1704 Jun 17 | 1758 Jul 20 | |
| Last | ||||
| Central | Total | Partial | Penumbral | |
1920 Oct 27 | 2155 Mar 19 | 2317 Jun 25 | 2443 Sep 09 | |
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 37–58 occur between 1801 and 2200: | |||||
|---|---|---|---|---|---|
| 37 | 38 | 39 | |||
| 1812 Aug 22 | 1830 Sep 02 | 1848 Sep 13 | |||
| 40 | 41 | 42 | |||
| 1866 Sep 24 | 1884 Oct 04 | 1902 Oct 17 | |||
 |  | ||||
| 43 | 44 | 45 | |||
| 1920 Oct 27 | 1938 Nov 07 | 1956 Nov 18 | |||
|  |  |  | | |
| 46 | 47 | 48 | |||
| 1974 Nov 29 | 1992 Dec 09 | 2010 Dec 21 | |||
 |  |  |  |  |  |
| 49 | 50 | 51 | |||
| 2028 Dec 31 | 2047 Jan 12 | 2065 Jan 22 | |||
 |  |  |  | ||
| 52 | 53 | 54 | |||
| 2083 Feb 02 | 2101 Feb 14 | 2119 Feb 25 | |||
| 55 | 56 | 57 | |||
| 2137 Mar 07 | 2155 Mar 19 | 2173 Mar 29 | |||
| 58 | |||||
| 2191 Apr 09 | |||||
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 2200 | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| 1804 Jan 26 (Saros 111) | 1814 Dec 26 (Saros 112) | 1825 Nov 25 (Saros 113) | 1836 Oct 24 (Saros 114) | 1847 Sep 24 (Saros 115) | |||||
| 1858 Aug 24 (Saros 116) | 1869 Jul 23 (Saros 117) | 1880 Jun 22 (Saros 118) | 1891 May 23 (Saros 119) | 1902 Apr 22 (Saros 120) | |||||
 |  | ||||||||
| 1913 Mar 22 (Saros 121) | 1924 Feb 20 (Saros 122) | 1935 Jan 19 (Saros 123) | 1945 Dec 19 (Saros 124) | 1956 Nov 18 (Saros 125) | |||||
 |  |  |  |  |  |  |  | | |
| 1967 Oct 18 (Saros 126) | 1978 Sep 16 (Saros 127) | 1989 Aug 17 (Saros 128) | 2000 Jul 16 (Saros 129) | 2011 Jun 15 (Saros 130) | |||||
 |  |  |  |  |  |  |  |  |  |
| 2022 May 16 (Saros 131) | 2033 Apr 14 (Saros 132) | 2044 Mar 13 (Saros 133) | 2055 Feb 11 (Saros 134) | 2066 Jan 11 (Saros 135) | |||||
 |  |  |  |  |  |  |  |  |  |
| 2076 Dec 10 (Saros 136) | 2087 Nov 10 (Saros 137) | 2098 Oct 10 (Saros 138) | 2109 Sep 09 (Saros 139) | 2120 Aug 09 (Saros 140) | |||||
 |  |  |  |  |  | ||||
| 2131 Jul 10 (Saros 141) | 2142 Jun 08 (Saros 142) | 2153 May 08 (Saros 143) | 2164 Apr 07 (Saros 144) | 2175 Mar 07 (Saros 145) | |||||
| 2186 Feb 04 (Saros 146) | 2197 Jan 04 (Saros 147) | ||||||||
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 | |||||
|---|---|---|---|---|---|
| 1812 Feb 27 (Saros 120) | 1841 Feb 06 (Saros 121) | 1870 Jan 17 (Saros 122) | |||
| 1898 Dec 27 (Saros 123) | 1927 Dec 08 (Saros 124) | 1956 Nov 18 (Saros 125) | |||
 |  | | | ||
| 1985 Oct 28 (Saros 126) | 2014 Oct 08 (Saros 127) | 2043 Sep 19 (Saros 128) | |||
 |  |  |  |  |  |
| 2072 Aug 28 (Saros 129) | 2101 Aug 09 (Saros 130) | 2130 Jul 21 (Saros 131) | |||
 |  | ||||
| 2159 Jun 30 (Saros 132) | 2188 Jun 09 (Saros 133) | ||||
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 132.
| November 12, 1947 | November 23, 1965 |
|---|---|
 |  |
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