December 1983 lunar eclipse
| Penumbral eclipse | |||||||||
 The Moon's hourly motion shown right to left | |||||||||
| Date | December 20, 1983 | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Gamma | 1.0747 | ||||||||
| Magnitude | −0.1167 | ||||||||
| Saros cycle | 144 (14 of 71) | ||||||||
| Penumbral | 242 minutes, 15 seconds | ||||||||
| |||||||||
A penumbral lunar eclipse occurred at the Moon’s ascending node of orbit on Tuesday, December 20, 1983,[1] with an umbral magnitude of −0.1167. 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 2.7 days before perigee (on December 22, 1983, at 18:25 UTC), the Moon's apparent diameter was larger.[2]
Visibility
The eclipse was completely visible over much of North America, South America, Europe, much of Africa, and west and north Asia, seen rising over western North America and the eastern Pacific Ocean and setting over southeast Africa and central and south 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 | 0.88903 |
| Umbral Magnitude | −0.11673 |
| Gamma | 1.07468 |
| Sun Right Ascension | 17h49m31.1s |
| Sun Declination | -23°25'11.7" |
| Sun Semi-Diameter | 16'15.5" |
| Sun Equatorial Horizontal Parallax | 08.9" |
| Moon Right Ascension | 05h48m58.9s |
| Moon Declination | +24°28'31.2" |
| Moon Semi-Diameter | 16'09.9" |
| Moon Equatorial Horizontal Parallax | 0°59'19.5" |
| ΔT | 53.7 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.
| December 4 Descending node (new moon) |
December 20 Ascending node (full moon) |
|---|---|
 |
|
| Annular solar eclipse Solar Saros 132 |
Penumbral lunar eclipse Lunar Saros 144 |
Related eclipses
Eclipses in 1983
- A total solar eclipse on June 11.
- A partial lunar eclipse on June 25.
- An annular solar eclipse on December 4.
- A penumbral lunar eclipse on December 20.
Metonic
- Preceded by: Lunar eclipse of March 1, 1980
- Followed by: Lunar eclipse of October 7, 1987
Tzolkinex
- Preceded by: Lunar eclipse of November 6, 1976
- Followed by: Lunar eclipse of January 30, 1991
Half-Saros
- Preceded by: Solar eclipse of December 13, 1974
- Followed by: Solar eclipse of December 24, 1992
Tritos
- Preceded by: Lunar eclipse of January 18, 1973
- Followed by: Lunar eclipse of November 18, 1994
Lunar Saros 144
- Preceded by: Lunar eclipse of December 8, 1965
- Followed by: Lunar eclipse of December 30, 2001
Inex
- Preceded by: Lunar eclipse of January 8, 1955
- Followed by: Lunar eclipse of November 28, 2012
Triad
- Preceded by: Lunar eclipse of February 17, 1897
- Followed by: Lunar eclipse of October 19, 2070
Lunar eclipses of 1980–1984
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 March 1, 1980 and August 26, 1980 occur in the previous lunar year eclipse set, and the penumbral lunar eclipses on May 15, 1984 and November 8, 1984 occur in the next lunar year eclipse set.
| Lunar eclipse series sets from 1980 to 1984 | ||||||||
|---|---|---|---|---|---|---|---|---|
| Descending node | Ascending node | |||||||
| Saros | Date Viewing |
Type Chart |
Gamma | Saros | Date Viewing |
Type Chart |
Gamma | |
| 109 | 1980 Jul 27
|
Penumbral
|
1.4139 | 114 | 1981 Jan 20
|
Penumbral
|
−1.0142 | |
| 119 | 1981 Jul 17
|
Partial
|
0.7045 | 124 | 1982 Jan 09
|
Total
|
−0.2916 | |
| 129 | 1982 Jul 06
|
Total
|
−0.0579 | 134 | 1982 Dec 30
|
Total
|
0.3758 | |
| 139 | 1983 Jun 25
|
Partial
|
−0.8152 | 144 | 1983 Dec 20
|
Penumbral
|
1.0747 | |
| 149 | 1984 Jun 13
|
Penumbral
|
−1.5240 | |||||
Saros 144
Lunar Saros series 144, repeating every 18 years and 11 days, has a total of 71 lunar eclipse events including 20 total lunar eclipses.
First Penumbral Lunar Eclipse: 1749 Jul 29
First Partial Lunar Eclipse: 2146 Mar 28
First Total Lunar Eclipse: 2308 Jul 04
First Central Lunar Eclipse: 2362 Aug 06
Greatest Eclipse of the Lunar Saros 144: 2416 Sep 07
Last Central Lunar Eclipse: 2488 Oct 20
Last Total Lunar Eclipse: 2651 Jan 28
Last Partial Lunar Eclipse: 2867 Jun 08
Last Penumbral Lunar Eclipse: 3011 Sep 04
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 partial solar eclipses of Solar Saros 151.
| December 13, 1974 | December 24, 1992 |
|---|---|
|
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See also
Notes
- ^ "December 19–20, 1983 Penumbral Lunar Eclipse". timeanddate. Retrieved 6 January 2025.
- ^ "Moon Distances for London, United Kingdom, England". timeanddate. Retrieved 6 January 2025.
- ^ "Penumbral Lunar Eclipse of 1983 Dec 20" (PDF). NASA. Retrieved 6 January 2025.
- ^ "Penumbral Lunar Eclipse of 1983 Dec 20". EclipseWise.com. Retrieved 6 January 2025.
- ^ 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
- 1983 Dec 20 chart Eclipse Predictions by Fred Espenak, NASA/GSFC