| Penumbral eclipse | |||||||||
 The Moon's hourly motion shown right to left | |||||||||
| Date | April 4, 1958 | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Gamma | −1.5381 | ||||||||
| Magnitude | −0.9421 | ||||||||
| Saros cycle | 102 (84 of 84) | ||||||||
| Penumbral | 31 minutes, 2 seconds | ||||||||
| |||||||||
A penumbrallunar eclipse occurred at the Moon’sascending node of orbit on Friday, April 4, 1958,[1] with an umbralmagnitude of −0.9421. 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 only about 16.5 hours beforeperigee (on April 3, 1958, at 20:30 UTC), the Moon's apparent diameter was larger.[2]
This was the last penumbral lunar eclipse inLunar Saros 102. In this extremely marginal eclipse, the Moon barely clipped the edge of the Earth's penumbral shadow. This caused a microscopic darkening of just 1% of the Moon's disc for about 31 minutes, which was essentially impossible to see.
The eclipse was completely visible overNorth America,South America, most ofAfrica andwestern Europe.[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 | 0.01359 |
| Umbral Magnitude | −0.94211 |
| Gamma | −1.53805 |
| Sun Right Ascension | 00h51m06.5s |
| Sun Declination | +05°28'40.0" |
| Sun Semi-Diameter | 15'59.5" |
| Sun Equatorial Horizontal Parallax | 08.8" |
| Moon Right Ascension | 12h49m12.4s |
| Moon Declination | -06°58'45.5" |
| Moon Semi-Diameter | 16'43.9" |
| Moon Equatorial Horizontal Parallax | 1°01'24.6" |
| ΔT | 32.4 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.
| April 4 Ascending node (full moon) | April 19 Descending node (new moon) | May 3 Ascending node (full moon) |
|---|---|---|
|  |  |
| Penumbral lunar eclipse Lunar Saros 102 | Annular solar eclipse Solar Saros 128 | Partial lunar eclipse Lunar Saros 140 |
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 lunar eclipses onMay 3, 1958 (partial) andOctober 28, 1958 (penumbral) occur in the previous lunar year eclipse set, and the penumbral lunar eclipse onJuly 17, 1962 occurs in the next lunar year eclipse set.
| Lunar eclipse series sets from 1958 to 1962 | ||||||||
|---|---|---|---|---|---|---|---|---|
| Ascending node | Descending node | |||||||
| Saros | Date Viewing | Type Chart | Gamma | Saros | Date Viewing | Type Chart | Gamma | |
| 102 | 1958 Apr 04 | Penumbral | −1.5381 | |||||
| 112 | 1959 Mar 24 | Partial | −0.8757 | 117 | 1959 Sep 17 | Penumbral | 1.0296 | |
| 122 | 1960 Mar 13 | Total | −0.1799 | 127 | 1960 Sep 05 | Total | 0.2422 | |
| 132 | 1961 Mar 02 | Partial | 0.5541 | 137 | 1961 Aug 26 | Partial | −0.4895 | |
| 142 | 1962 Feb 19 | Penumbral | 1.2512 | 147 | 1962 Aug 15 | Penumbral | −1.2210 | |
This eclipse is a part ofSaros series 102, repeating every 18 years, 11 days, and containing 84 events. The series started with a penumbral lunar eclipse on October 5, 461 AD. It contains partial eclipses from May 20, 840, through July 13, 930; total eclipses from July 23, 948, through April 20, 1399; and a second set of partial eclipses from May 1, 1417, through July 16, 1543. The series ends at member 84 as a penumbral eclipse onApril 4, 1958.
The longest duration of totality was produced by member 36 at 104 minutes, 43 seconds, on October 7, 1074. All eclipses in this series occur at the Moon’sascending node of orbit.[6]
| Greatest | First | |||
|---|---|---|---|---|
| The greatest eclipse of the series occurred on1074 Oct 07, lasting 104 minutes, 43 seconds.[7] | Penumbral | Partial | Total | Central |
| 461 Oct 05 | 840 May 20 | 948 Jul 23 | 984 Aug 14 | |
| Last | ||||
| Central | Total | Partial | Penumbral | |
| 1345 Mar 18 | 1399 Apr 20 | 1543 Jul 16 | 1958 Apr 04 | |
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 76–84 occur between 1801 and 1958: | |||||
|---|---|---|---|---|---|
| 76 | 77 | 78 | |||
| 1814 Jan 06 | 1832 Jan 17 | 1850 Jan 28 | |||
| 79 | 80 | 81 | |||
| 1868 Feb 08 | 1886 Feb 18 | 1904 Mar 02 | |||
 |  | ||||
| 82 | 83 | 84 | |||
| 1922 Mar 13 | 1940 Mar 23 | 1958 Apr 04 | |||
 |  |  |  | | |
 | This lunar eclipse-related article is astub. You can help Wikipedia byexpanding it. |
_(cropped).jpg)
