| Penumbral eclipse | |||||||||
 The Moon's hourly motion shown right to left | |||||||||
| Date | January 8, 1955 | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Gamma | −1.0907 | ||||||||
| Magnitude | −0.1421 | ||||||||
| Saros cycle | 143 (15 of 73) | ||||||||
| Penumbral | 236 minutes, 2 seconds | ||||||||
| |||||||||
A penumbrallunar eclipse occurred at the Moon’sdescending node of orbit on Saturday, January 8, 1955,[1] with an umbralmagnitude of −0.1421. 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 2.2 days afterperigee (on January 6, 1955, at 8:55 UTC), the Moon's apparent diameter was larger.[2]
The eclipse was completely visible overeast andnorth Asia,Australia, and northwesternNorth America, seen rising over much of the western half ofAsia andnorthern Europe and setting over eastern North America and northwesternSouth America.[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 | 0.85553 |
| Umbral Magnitude | −0.14209 |
| Gamma | −1.09070 |
| Sun Right Ascension | 19h15m41.7s |
| Sun Declination | -22°18'18.6" |
| Sun Semi-Diameter | 16'15.9" |
| Sun Equatorial Horizontal Parallax | 08.9" |
| Moon Right Ascension | 07h14m38.8s |
| Moon Declination | +21°14'42.2" |
| Moon Semi-Diameter | 16'18.2" |
| Moon Equatorial Horizontal Parallax | 0°59'50.2" |
| ΔT | 31.1 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.
| December 25 Ascending node (new moon) | January 8 Descending node (full moon) |
|---|---|
 | |
| Annular solar eclipse Solar Saros 131 | Penumbral lunar eclipse Lunar Saros 143 |
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 eclipses onMarch 23, 1951 andSeptember 15, 1951 occur in the previous lunar year eclipse set, and the lunar eclipses onJune 5, 1955 (penumbral) andNovember 29, 1955 (partial) occur in the next lunar year eclipse set.
| Lunar eclipse series sets from 1951 to 1955 | ||||||||
|---|---|---|---|---|---|---|---|---|
| Descending node | Ascending node | |||||||
| Saros | Date Viewing | Type Chart | Gamma | Saros | Date Viewing | Type Chart | Gamma | |
| 103 | 1951 Feb 21 | Penumbral | − | 108 | 1951 Aug 17 | Penumbral | −1.4828 | |
| 113 | 1952 Feb 11 | Partial | 0.9416 | 118 | 1952 Aug 05 | Partial | −0.7384 | |
| 123 | 1953 Jan 29 | Total | 0.2606 | 128 | 1953 Jul 26 | Total | −0.0071 | |
| 133 | 1954 Jan 19 | Total | −0.4357 | 138 | 1954 Jul 16 | Partial | 0.7877 | |
| 143 | 1955 Jan 08 | Penumbral | −1.0907 | |||||
This eclipse is a part ofSaros series 143, repeating every 18 years, 11 days, and containing 72 events. The series started with a penumbral lunar eclipse on August 18, 1720. It contains partial eclipses fromMarch 14, 2063 through June 21, 2225; total eclipses from July 2, 2243 through April 13, 2712; and a second set of partial eclipses from April 25, 2730 through July 9, 2856. The series ends at member 72 as a penumbral eclipse on October 5, 3000.
The longest duration of totality will be produced by member 36 at 99 minutes, 9 seconds on September 6, 2351. All eclipses in this series occur at the Moon’sdescending node of orbit.[6]
| Greatest | First | |||
|---|---|---|---|---|
| The greatest eclipse of the series will occur on2351 Sep 06, lasting 99 minutes, 9 seconds.[7] | Penumbral | Partial | Total | Central |
| 1720 Aug 18 | 2063 Mar 14 | 2243 Jul 02 | 2297 Aug 03 | |
| Last | ||||
| Central | Total | Partial | Penumbral | |
| 2495 Dec 02 | 2712 Apr 13 | 2856 Jul 09 | 3000 Oct 05 | |
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 6–27 occur between 1801 and 2200: | |||||
|---|---|---|---|---|---|
| 6 | 7 | 8 | |||
| 1810 Oct 12 | 1828 Oct 23 | 1846 Nov 03 | |||
| 9 | 10 | 11 | |||
| 1864 Nov 13 | 1882 Nov 25 | 1900 Dec 06 | |||
| 12 | 13 | 14 | |||
| 1918 Dec 17 | 1936 Dec 28 | 1955 Jan 08 | |||
 |  |  |  | | |
| 15 | 16 | 17 | |||
| 1973 Jan 18 | 1991 Jan 30 | 2009 Feb 09 | |||
 |  |  |  |  |  |
| 18 | 19 | 20 | |||
| 2027 Feb 20 | 2045 Mar 03 | 2063 Mar 14 | |||
 |  |  |  | ||
| 21 | 22 | 23 | |||
| 2081 Mar 25 | 2099 Apr 05 | 2117 Apr 16 | |||
 |  | ||||
| 24 | 25 | 26 | |||
| 2135 Apr 28 | 2153 May 08 | 2171 May 19 | |||
| 27 | |||||
| 2189 May 29 | |||||
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 2096 | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| 1802 Mar 19 (Saros 129) | 1813 Feb 15 (Saros 130) | 1824 Jan 16 (Saros 131) | 1834 Dec 16 (Saros 132) | 1845 Nov 14 (Saros 133) | |||||
| 1856 Oct 13 (Saros 134) | 1867 Sep 14 (Saros 135) | 1878 Aug 13 (Saros 136) | 1889 Jul 12 (Saros 137) | 1900 Jun 13 (Saros 138) | |||||
| 1911 May 13 (Saros 139) | 1922 Apr 11 (Saros 140) | 1933 Mar 12 (Saros 141) | 1944 Feb 09 (Saros 142) | 1955 Jan 08 (Saros 143) | |||||
 |  |  |  |  |  |  |  | | |
| 1965 Dec 08 (Saros 144) | 1976 Nov 06 (Saros 145) | 1987 Oct 07 (Saros 146) | 1998 Sep 06 (Saros 147) | 2009 Aug 06 (Saros 148) | |||||
 |  |  |  |  |  |  |  |  |  |
| 2020 Jul 05 (Saros 149) | 2031 Jun 05 (Saros 150) | ||||||||
 |  |  |  | ||||||
| 2096 Nov 29 (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 | |||||
|---|---|---|---|---|---|
| 1810 Apr 19 (Saros 138) | 1839 Mar 30 (Saros 139) | 1868 Mar 08 (Saros 140) | |||
| 1897 Feb 17 (Saros 141) | 1926 Jan 28 (Saros 142) | 1955 Jan 08 (Saros 143) | |||
 |  | | | ||
| 1983 Dec 20 (Saros 144) | 2012 Nov 28 (Saros 145) | 2041 Nov 08 (Saros 146) | |||
 |  |  |  |  |  |
| 2070 Oct 19 (Saros 147) | 2099 Sep 29 (Saros 148) | 2128 Sep 09 (Saros 149) | |||
 |  |  |  | ||
| 2157 Aug 20 (Saros 150) | 2186 Jul 31 (Saros 151) | ||||
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 150.
| January 3, 1946 | January 14, 1964 |
|---|---|
 |  |
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