| Penumbral eclipse | |||||||||
 The Moon's hourly motion shown right to left | |||||||||
| Date | September 25, 1969 | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Gamma | 1.0656 | ||||||||
| Magnitude | −0.0952 | ||||||||
| Saros cycle | 146 (8 of 72) | ||||||||
| Penumbral | 245 minutes, 9 seconds | ||||||||
| |||||||||
A penumbrallunar eclipse occurred at the Moon’sascending node of orbit on Thursday, September 25, 1969,[1] with an umbralmagnitude of −0.0952. A lunar eclipse occurs when theMoon moves into theEarth'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 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. Occurring about 3.4 days afterperigee (on September 22, 1969, at 11:45 UTC), the Moon's apparent diameter was larger.[2]
The eclipse was completely visible overEurope,Africa, andAsia, seen rising over easternSouth America andwest Africa and setting overnortheast Asia andAustralia.[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 | 0.90080 |
| Umbral Magnitude | −0.09519 |
| Gamma | 1.06558 |
| Sun Right Ascension | 12h09m26.5s |
| Sun Declination | -01°01'23.8" |
| Sun Semi-Diameter | 15'57.2" |
| Sun Equatorial Horizontal Parallax | 08.8" |
| Moon Right Ascension | 00h07m25.1s |
| Moon Declination | +01°56'11.3" |
| Moon Semi-Diameter | 16'01.1" |
| Moon Equatorial Horizontal Parallax | 0°58'47.2" |
| ΔT | 39.9 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. The first and last eclipse in this sequence is separated by onesynodic month.
| August 27 Ascending node (full moon) | September 11 Descending node (new moon) | September 25 Ascending node (full moon) |
|---|---|---|
 |  | |
| Penumbral lunar eclipse Lunar Saros 108 | Annular solar eclipse Solar Saros 134 | Penumbral lunar eclipse Lunar Saros 146 |
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 onAugust 27, 1969 occurs in the next lunar year eclipse set.
| Lunar eclipse series sets from 1966 to 1969 | ||||||||
|---|---|---|---|---|---|---|---|---|
| Descending node | Ascending node | |||||||
| Saros | Date Viewing | Type Chart | Gamma | Saros | Date Viewing | Type Chart | Gamma | |
| 111 | 1966 May 04 | Penumbral | 1.0554 | 116 | 1966 Oct 29 | Penumbral | −1.0600 | |
| 121 | 1967 Apr 24 | Total | 0.2972 | 126 | 1967 Oct 18 | Total | −0.3653 | |
| 131 | 1968 Apr 13 | Total | −0.4173 | 136 | 1968 Oct 06 | Total | 0.3605 | |
| 141 | 1969 Apr 02 | Penumbral | −1.1765 | 146 | 1969 Sep 25 | Penumbral | 1.0656 | |
This eclipse is a part ofSaros series 146, repeating every 18 years, 11 days, and containing 72 events. The series started with a penumbral lunar eclipse on July 11, 1843. It contains partial eclipses fromOctober 17, 2005 through May 14, 2348; total eclipses from May 25, 2366 through November 16, 2654; and a second set of partial eclipses from November 27, 2672 through June 12, 2997. The series ends at member 72 as a penumbral eclipse on August 29, 3123.
The longest duration of totality will be produced by member 37 at 99 minutes, 22 seconds on August 8, 2492. All eclipses in this series occur at the Moon’sascending node of orbit.[6]
| Greatest | First | |||
|---|---|---|---|---|
| The greatest eclipse of the series will occur on2492 Aug 08, lasting 99 minutes, 22 seconds.[7] | Penumbral | Partial | Total | Central |
| 1843 Jul 11 | 2005 Oct 17 | 2366 May 25 | 2438 Jul 07 | |
| Last | ||||
| Central | Total | Partial | Penumbral | |
| 2546 Sep 11 | 2654 Nov 16 | 2997 Jun 12 | 3123 Aug 29 | |
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 1–20 occur between 1843 and 2200: | |||||
|---|---|---|---|---|---|
| 1 | 2 | 3 | |||
| 1843 Jul 11 | 1861 Jul 21 | 1879 Aug 02 | |||
| 4 | 5 | 6 | |||
| 1897 Aug 12 | 1915 Aug 24 | 1933 Sep 04 | |||
 |  |  |  | ||
| 7 | 8 | 9 | |||
| 1951 Sep 15 | 1969 Sep 25 | 1987 Oct 07 | |||
 |  | | |  |  |
| 10 | 11 | 12 | |||
| 2005 Oct 17 | 2023 Oct 28 | 2041 Nov 08 | |||
|  |  |  |  |  |
| 13 | 14 | 15 | |||
| 2059 Nov 19 | 2077 Nov 29 | 2095 Dec 11 | |||
 |  | ||||
| 16 | 17 | 18 | |||
| 2113 Dec 22 | 2132 Jan 02 | 2150 Jan 13 | |||
| 19 | 20 | ||||
| 2168 Jan 24 | 2186 Feb 04 | ||||
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 2078 | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| 1806 Jan 05 (Saros 131) | 1816 Dec 04 (Saros 132) | 1827 Nov 03 (Saros 133) | 1838 Oct 03 (Saros 134) | 1849 Sep 02 (Saros 135) | |||||
| 1860 Aug 01 (Saros 136) | 1871 Jul 02 (Saros 137) | 1882 Jun 01 (Saros 138) | 1893 Apr 30 (Saros 139) | 1904 Mar 31 (Saros 140) | |||||
 |  | ||||||||
| 1915 Mar 01 (Saros 141) | 1926 Jan 28 (Saros 142) | 1936 Dec 28 (Saros 143) | 1947 Nov 28 (Saros 144) | 1958 Oct 27 (Saros 145) | |||||
 |  |  |  |  |  |  |  |  |  |
| 1969 Sep 25 (Saros 146) | 1980 Aug 26 (Saros 147) | 1991 Jul 26 (Saros 148) | 2002 Jun 24 (Saros 149) | 2013 May 25 (Saros 150) | |||||
| |  |  |  |  |  |  |  |  |
| 2078 Nov 19 (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 | |||||
|---|---|---|---|---|---|
| 1825 Jan 04 (Saros 141) | 1853 Dec 15 (Saros 142) | 1882 Nov 25 (Saros 143) | |||
| 1911 Nov 06 (Saros 144) | 1940 Oct 16 (Saros 145) | 1969 Sep 25 (Saros 146) | |||
 |  |  |  | | |
| 1998 Sep 06 (Saros 147) | 2027 Aug 17 (Saros 148) | 2056 Jul 26 (Saros 149) | |||
 |  |  |  |  |  |
| 2085 Jul 07 (Saros 150) | 2114 Jun 18 (Saros 151) | 2143 May 28 (Saros 152) | |||
| 2172 May 08 (Saros 153) | |||||
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 partial solar eclipses ofSolar Saros 153.
| September 20, 1960 | October 2, 1978 |
|---|---|
 |  |
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