October 1948 lunar eclipse
| Penumbral eclipse | |||||||||
 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
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]
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Eclipse details
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 | 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
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) |
|---|---|
|
|
| Penumbral lunar eclipse Lunar Saros 116 |
Total solar eclipse Solar Saros 142 |
Related eclipses
Eclipses in 1948
- 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
- Preceded by: Lunar eclipse of December 29, 1944
- Followed by: Lunar eclipse of August 5, 1952
Tzolkinex
- Preceded by: Lunar eclipse of September 5, 1941
- Followed by: Lunar eclipse of November 29, 1955
Half-Saros
- Preceded by: Solar eclipse of October 12, 1939
- Followed by: Solar eclipse of October 23, 1957
Tritos
- Preceded by: Lunar eclipse of November 18, 1937
- Followed by: Lunar eclipse of September 17, 1959
Lunar Saros 116
- Preceded by: Lunar eclipse of October 7, 1930
- Followed by: Lunar eclipse of October 29, 1966
Inex
- Preceded by: Lunar eclipse of November 7, 1919
- Followed by: Lunar eclipse of September 27, 1977
Triad
- Preceded by: Lunar eclipse of December 17, 1861
- Followed by: Lunar eclipse of August 19, 2035
Lunar eclipses of 1948–1951
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.
| Lunar eclipse series sets from 1948 to 1951 | ||||||||
|---|---|---|---|---|---|---|---|---|
| Descending node | Ascending node | |||||||
| Saros | Date Viewing |
Type Chart |
Gamma | Saros | Date Viewing |
Type Chart |
Gamma | |
| 111 | 1948 Apr 23
|
Partial
|
1.0017 | 116 | 1948 Oct 18
|
Penumbral
|
−1.0245 | |
| 121 | 1949 Apr 13
|
Total
|
0.2474 | 126 | 1949 Oct 07
|
Total
|
−0.3219 | |
| 131 | 1950 Apr 02
|
Total
|
−0.4599 | 136 | 1950 Sep 26
|
Total
|
0.4101 | |
| 141 | 1951 Mar 23
|
Penumbral
|
−1.2099 | 146 | 1951 Sep 15
|
Penumbral
|
1.1187 | |
Half-Saros cycle
A lunar eclipse will be preceded and followed by solar eclipses by 9 years and 5.5 days (a half saros).[6] This lunar eclipse is related to two total solar eclipses of Solar Saros 123.
| October 12, 1939 | October 23, 1957 |
|---|---|
|
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See also
Notes
- ^ "October 17–18, 1948 Penumbral Lunar Eclipse". timeanddate. Retrieved 21 December 2024.
- ^ "Moon Distances for London, United Kingdom, England". timeanddate. Retrieved 21 December 2024.
- ^ "Penumbral Lunar Eclipse of 1948 Oct 18" (PDF). NASA. Retrieved 21 December 2024.
- ^ "Penumbral Lunar Eclipse of 1948 Oct 18". EclipseWise.com. Retrieved 21 December 2024.
- ^ van Gent, R.H. "Solar- and Lunar-Eclipse Predictions from Antiquity to the Present". A Catalogue of Eclipse Cycles. Utrecht University. Retrieved 6 October 2018.
- ^ Mathematical Astronomy Morsels, Jean Meeus, p.110, Chapter 18, The half-saros
External links
- 1948 Oct 18 chart Eclipse Predictions by Fred Espenak, NASA/GSFC
