December 1973 lunar eclipse
A partial lunar eclipse occurred at the Moon’s descending node of orbit on Monday, December 10, 1973, with an umbral magnitude of 0.1007. A lunar eclipse occurs when the Moon moves into the Earth's shadow, causing the Moon to be darkened. A partial lunar eclipse occurs when one part of the Moon is in the Earth's umbra, while the other part is in 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 only about 21 hours before perigee, the Moon's apparent diameter was larger.
This eclipse was the last of four lunar eclipses in 1973, with the others occurring on January 18, June 15, and July 15.
Visibility
The eclipse was completely visible over much of North and South America, Africa, Europe, and west and north Asia, seen rising over western North America and the eastern Pacific Ocean and setting over southeast Africa and much of Asia.Eclipse details
Shown below is a table displaying details about this particular lunar eclipse. It describes various parameters pertaining to this eclipse.| Parameter | Value |
| Penumbral Magnitude | 1.07597 |
| Umbral Magnitude | 0.10069 |
| Gamma | 0.96441 |
| Sun Right Ascension | 17h07m12.8s |
| Sun Declination | -22°53'16.9" |
| Sun Semi-Diameter | 16'14.5" |
| Sun Equatorial Horizontal Parallax | 08.9" |
| Moon Right Ascension | 05h07m14.5s |
| Moon Declination | +23°52'13.3" |
| Moon Semi-Diameter | 16'39.2" |
| Moon Equatorial Horizontal Parallax | 1°01'07.2" |
| ΔT | 44.3 s |
Eclipse season
This eclipse is part of an eclipse season, a period, roughly every six months, when eclipses occur. Only two eclipse seasons occur each year, and each season lasts about 35 days and repeats just short of six months 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 10 Descending node | December 24 Ascending node |
| Partial lunar eclipse Lunar Saros 115 | Annular solar eclipse Solar Saros 141 |
Related eclipses
Eclipses in 1973
- An annular solar eclipse on January 4.
- A penumbral lunar eclipse on January 18.
- A penumbral lunar eclipse on June 15.
- A total solar eclipse on June 30.
- A penumbral lunar eclipse on July 15.A partial lunar eclipse on December 10.
- An annular solar eclipse on December 24.
Metonic
- Preceded by: Lunar eclipse of February 21, 1970
- Followed by: Lunar eclipse of September 27, 1977
Tzolkinex
- Preceded by: Lunar eclipse of October 29, 1966
- Followed by: Lunar eclipse of January 20, 1981
Half-Saros
- Preceded by: Solar eclipse of December 4, 1964
- Followed by: Solar eclipse of December 15, 1982
Tritos
- Preceded by: Lunar eclipse of January 9, 1963
- Followed by: Lunar eclipse of November 8, 1984
Lunar Saros 115
- Preceded by: Lunar eclipse of November 29, 1955
- Followed by: Lunar eclipse of December 21, 1991
Inex
- Preceded by: Lunar eclipse of December 29, 1944
- Followed by: Lunar eclipse of November 20, 2002
Triad
- Preceded by: Lunar eclipse of February 8, 1887
- Followed by: Lunar eclipse of October 9, 2060
Half-Saros cycle
A lunar eclipse will be preceded and followed by solar eclipses by 9 years and 5.5 days. This lunar eclipse is related to two partial solar eclipses of Solar Saros 122.| December 4, 1964 | December 15, 1982 |