October 1948 lunar eclipse
| Penumbral eclipse | |||||||||
| File:Lunar eclipse chart close-1948Oct18.png The Moon's hourly motion shown right to left | |||||||||
| Date | October 18, 1948 | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Gamma | −1.0245 | ||||||||
| Magnitude | −0.0571 | ||||||||
| Saros cycle | 116 (54 of 73) | ||||||||
| Penumbral | 279 minutes, 41 seconds | ||||||||
| |||||||||
A penumbral lunar eclipse occurred at the Moon’s ascending node of orbit on Monday, October 18, 1948,[1] with an umbral magnitude of −0.0571. It was a relatively rare total penumbral lunar eclipse, with the Moon passing entirely within the penumbral shadow without entering the darker umbral shadow. 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 4.2 days after apogee (on October 13, 1948, at 22:15 UTC), the Moon's apparent diameter was smaller.[2]
Visibility
[edit | edit source]The eclipse was completely visible over eastern North America, South America, west Africa, and western Europe, seen rising over western North America and the eastern Pacific Ocean and setting over east Africa, eastern Europe, and the western half of Asia.[3]
| File:Lunar eclipse from moon-1948Oct18.png File:Lunar eclipse chart close-1948Oct18.png |
Eclipse details
[edit | edit source]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 | 1.01405 |
| Umbral Magnitude | −0.05712 |
| Gamma | −1.02452 |
| Sun Right Ascension | 13h31m13.7s |
| Sun Declination | -09°32'38.5" |
| Sun Semi-Diameter | 16'03.4" |
| Sun Equatorial Horizontal Parallax | 08.8" |
| Moon Right Ascension | 01h32m57.9s |
| Moon Declination | +08°42'28.9" |
| Moon Semi-Diameter | 14'59.4" |
| Moon Equatorial Horizontal Parallax | 0°55'00.9" |
| ΔT | 28.6 s |
Eclipse season
[edit | edit source]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.
| October 18 Ascending node (full moon) |
November 1 Descending node (new moon) |
|---|---|
| File:Lunar eclipse chart close-1948Oct18.png | File:SE1948Nov01T.png |
| Penumbral lunar eclipse Lunar Saros 116 |
Total solar eclipse Solar Saros 142 |
Related eclipses
[edit | edit source]Eclipses in 1948
[edit | edit source]- A partial lunar eclipse on April 23.
- An annular solar eclipse on May 9.
- A penumbral lunar eclipse on October 18.
- A total solar eclipse on November 1.
Metonic
[edit | edit source]- Preceded by: Lunar eclipse of December 29, 1944
- Followed by: Lunar eclipse of August 5, 1952
Tzolkinex
[edit | edit source]- Preceded by: Lunar eclipse of September 5, 1941
- Followed by: Lunar eclipse of November 29, 1955
Half-Saros
[edit | edit source]- Preceded by: Solar eclipse of October 12, 1939
- Followed by: Solar eclipse of October 23, 1957
Tritos
[edit | edit source]- Preceded by: Lunar eclipse of November 18, 1937
- Followed by: Lunar eclipse of September 17, 1959
Lunar Saros 116
[edit | edit source]- Preceded by: Lunar eclipse of October 7, 1930
- Followed by: Lunar eclipse of October 29, 1966
Inex
[edit | edit source]- Preceded by: Lunar eclipse of November 7, 1919
- Followed by: Lunar eclipse of September 27, 1977
Triad
[edit | edit source]- Preceded by: Lunar eclipse of December 17, 1861
- Followed by: Lunar eclipse of August 19, 2035
Lunar eclipses of 1948–1951
[edit | edit source]This eclipse is a member of a semester series. An eclipse in a semester series of lunar eclipses repeats approximately every 177 days and 4 hours (a semester) at alternating nodes of the Moon's orbit.[5]
The penumbral lunar eclipses on February 21, 1951 and August 17, 1951 occur in the next lunar year eclipse set.
Saros 116
[edit | edit source]This eclipse is a part of Saros series 116, repeating every 18 years, 11 days, and containing 73 events. The series started with a penumbral lunar eclipse on March 11, 993 AD. It contains partial eclipses from June 16, 1155 through September 11, 1299; total eclipses from September 21, 1317 through July 11, 1786; and a second set of partial eclipses from July 22, 1804 through October 7, 1930. The series ends at member 73 as a penumbral eclipse on May 14, 2291.
The longest duration of totality was produced by member 40 at 102 minutes, 40 seconds on May 16, 1696. All eclipses in this series occur at the Moon’s ascending node of orbit.[6]
| Greatest | First | |||
|---|---|---|---|---|
| The greatest eclipse of the series occurred on 1696 May 16, lasting 102 minutes, 40 seconds.[7] | Penumbral | Partial | Total | Central |
| 993 Mar 11 |
1155 Jun 16 |
1317 Sep 21 |
1588 Mar 13 | |
| Last | ||||
| Central | Total | Partial | Penumbral | |
| 1750 Jun 19 |
1786 Jul 11 |
1930 Oct 07 File:Lunar eclipse chart close-1930Oct07.png |
2291 May 14 | |
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.
Tritos series
[edit | edit source]This eclipse is a part of a tritos cycle, repeating at alternating nodes every 135 synodic months (≈ 3986.63 days, or 11 years minus 1 month). Their appearance and longitude are irregular due to a lack of synchronization with the anomalistic 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.
Inex series
[edit | edit source]This eclipse is a part of the long period inex cycle, repeating at alternating nodes, every 358 synodic months (≈ 10,571.95 days, or 29 years minus 20 days). Their appearance and longitude are irregular due to a lack of synchronization with the anomalistic 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 | |||||
|---|---|---|---|---|---|
| 1804 Jan 26 (Saros 111) |
1833 Jan 06 (Saros 112) |
1861 Dec 17 (Saros 113) | |||
| 1890 Nov 26 (Saros 114) |
1919 Nov 07 (Saros 115) |
1948 Oct 18 (Saros 116) | |||
| File:Lunar eclipse chart close-1919Nov07.png | File:Lunar eclipse from moon-1919Nov07.png | File:Lunar eclipse chart close-1948Oct18.png | File:Lunar eclipse from moon-1948Oct18.png | ||
| 1977 Sep 27 (Saros 117) |
2006 Sep 07 (Saros 118) |
2035 Aug 19 (Saros 119) | |||
| File:Lunar eclipse chart close-1977Sep27.png | File:Lunar eclipse from moon-1977Sep27.png | File:Lunar eclipse chart close-2006Sep07.png | File:Lunar eclipse from moon-2006Sep07.png | File:Lunar eclipse chart close-2035Aug19.png | File:Lunar eclipse from moon-2035Aug19.png |
| 2064 Jul 28 (Saros 120) |
2093 Jul 08 (Saros 121) |
2122 Jun 20 (Saros 122) | |||
| 2151 May 30 (Saros 123) |
2180 May 09 (Saros 124) | ||||
Half-Saros cycle
[edit | edit source]A lunar eclipse will be preceded and followed by solar eclipses by 9 years and 5.5 days (a half saros).[8] This lunar eclipse is related to two total solar eclipses of Solar Saros 123.
| October 12, 1939 | October 23, 1957 |
|---|---|
| File:SE1939Oct12T.png | File:SE1957Oct23T.png |
See also
[edit | edit source]Notes
[edit | edit source]- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Listing of Eclipses of series 116
- ^ Mathematical Astronomy Morsels, Jean Meeus, p.110, Chapter 18, The half-saros
External links
[edit | edit source]- 1948 Oct 18 chart Eclipse Predictions by Fred Espenak, NASA/GSFC
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