| Type: | penumbral |
| Date: | February 21, 1951 |
| Gamma: | - |
| Magnitude: | 0.007 (penumbral magnitude) |
| Saros Ser: | 103 |
| Saros No: | 84 of 84 |
| Penumbral: | - |
| P1: | - |
| Greatest: | 21:12 |
| P4: | - |
| Previous: | September 1950 |
| Next: | March 1951 |
A penumbral lunar eclipse occurred at the Moon’s descending node of orbit on Wednesday, February 21, 1951,[1] with a penumbral magnitude of 0.007. 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 about 6.5 days after apogee (on February 15, 1951, at 9:35 UTC), the Moon's apparent diameter was smaller.[2]
This eclipse was the first of four penumbral lunar eclipses in 1951, with the others occurring on March 23, August 17, and September 15.
The magnitude of the eclipse was 0.007 or a miss depending on definitions of the penumbral shadow is defined. Bao-Lin Lui's Canon of lunar eclipses list it as the last eclipse of a saros cycle, with magnitude 0.007, while NASA lists February 10, 1933, as the final series event, with this one missing the shadow.[3]
As seen from the lunar south pole the sun missing the sphere of the earth, excluding the atmosphere.
The eclipse was completely visible over Africa, Europe, and much of Asia.
See also: Eclipse cycle. 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.
This eclipse is a part of Saros series 103, repeating every 18 years, 11 days, and containing 82 or 83 events (depending on the source). The series started with a penumbral lunar eclipse on September 3, 472 AD. It contains partial eclipses from April 19, 851 AD through June 23, 959 AD; total eclipses from July 3, 977 AD through May 3, 1482; and a second set of partial eclipses from May 13, 1500 through July 27, 1608. The series ends at member 82 as a penumbral eclipse on February 10, 1933, though some sources count a possible penumbral eclipse on February 21, 1951 as the last eclipse of the series.
The longest duration of totality was produced by member 36 at 98 minutes, 57 seconds on September 17, 1103. All eclipses in this series occur at the Moon’s descending node of orbit.[4]
| Greatest | First | |||
|---|---|---|---|---|
| The greatest eclipse of the series occurred on 1103 Sep 17, lasting 98 minutes, 57 seconds.[5] | Penumbral | Partial | Total | Central |
| 472 Sep 03 | 851 Apr 19 | 977 Jul 03 | 1031 Aug 05 | |
| Last | ||||
| Central | Total | Partial | Penumbral | |
| 1410 Mar 21 | 1482 May 03 | 1608 Jul 27 | 1933 Feb 10 | |
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 75–83 occur between 1801 and 1951: | ||||||
|---|---|---|---|---|---|---|
| 75 | 76 | 77 | ||||
| 1806 Nov 26 | 1824 Dec 06 | 1842 Dec 17 | ||||
| 78 | 79 | 80 | ||||
| 1860 Dec 28 | 1879 Jan 08 | 1897 Jan 18 | ||||
| 81 | 82 | 83 | ||||
| 1915 Jan 31 | 1933 Feb 10 | 1951 Feb 21 | ||||
