January 1973 lunar eclipse
A penumbral lunar eclipse occurred at the Moon’s descending node of orbit on Thursday, January 18, 1973, with an umbral magnitude of −0.1292. 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 days after perigee, the Moon's apparent diameter was larger.
This eclipse was the first of four lunar eclipses in 1973, with the others occurring on June 15, July 15, and December 10.
Visibility
The eclipse was completely visible over Europe, Africa, and Asia, seen rising over eastern North America and much of South America and setting over east Asia and Australia.Eclipse details
Shown below is a table displaying details about this particular solar eclipse. It describes various parameters pertaining to this eclipse.| Parameter | Value |
| Penumbral Magnitude | 0.86555 |
| Umbral Magnitude | −0.12922 |
| Gamma | −1.08446 |
| Sun Right Ascension | 20h03m09.2s |
| Sun Declination | -20°25'53.6" |
| Sun Semi-Diameter | 16'15.4" |
| Sun Equatorial Horizontal Parallax | 08.9" |
| Moon Right Ascension | 08h01m47.2s |
| Moon Declination | +19°23'46.9" |
| Moon Semi-Diameter | 16'20.5" |
| Moon Equatorial Horizontal Parallax | 0°59'58.5" |
| ΔT | 43.4 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.| January 4 Ascending node | January 18 Descending node |
| Annular solar eclipse Solar Saros 131 | Penumbral lunar eclipse Lunar Saros 143 |
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 April 2, 1969
- Followed by: Lunar eclipse of November 6, 1976
Tzolkinex
- Preceded by: Lunar eclipse of December 8, 1965
- Followed by: Lunar eclipse of March 1, 1980
Half-Saros
- Preceded by: Solar eclipse of January 14, 1964
- Followed by: Solar eclipse of January 25, 1982
Tritos
- Preceded by: Lunar eclipse of February 19, 1962
- Followed by: Lunar eclipse of December 20, 1983
Lunar Saros 143
- Preceded by: Lunar eclipse of January 8, 1955
- Followed by: Lunar eclipse of January 30, 1991
Inex
- Preceded by: Lunar eclipse of February 9, 1944
- Followed by: Lunar eclipse of December 30, 2001
Triad
- Preceded by: Lunar eclipse of March 20, 1886
- Followed by: Lunar eclipse of November 19, 2059
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 150.| January 14, 1964 | January 25, 1982 |