January 1981 lunar eclipse
A penumbral lunar eclipse occurred at the Moon’s ascending node of orbit on Tuesday, January 20, 1981, with an umbral magnitude of −0.0192. 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 5.2 days after perigee, the Moon's apparent diameter was larger.
Visibility
The eclipse was completely visible over northeast Asia, North America, and western South America, seen rising over east Asia and eastern Australia and setting over eastern South America, west Africa and much of Europe.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 | 1.01360 |
| Umbral Magnitude | −0.01916 |
| Gamma | −1.01421 |
| Sun Right Ascension | 20h09m28.4s |
| Sun Declination | -20°06'46.4" |
| Sun Semi-Diameter | 16'15.2" |
| Sun Equatorial Horizontal Parallax | 08.9" |
| Moon Right Ascension | 08h08m59.5s |
| Moon Declination | +19°08'35.7" |
| Moon Semi-Diameter | 15'44.3" |
| Moon Equatorial Horizontal Parallax | 0°57'45.5" |
| ΔT | 51.4 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 20 Ascending node | February 4 Descending node |
| Penumbral lunar eclipse Lunar Saros 114 | Annular solar eclipse Solar Saros 140 |
Related eclipses
Eclipses in 1981
- A penumbral lunar eclipse on January 20.
- An annular solar eclipse on February 4.
- A partial lunar eclipse on July 17.
- A total solar eclipse on July 31.
Metonic
- Preceded by: Lunar eclipse of April 4, 1977
- Followed by: Lunar eclipse of November 8, 1984
Tzolkinex
- Preceded by: Lunar eclipse of December 10, 1973
- Followed by: Lunar eclipse of March 3, 1988
Half-Saros
- Preceded by: Solar eclipse of January 16, 1972
- Followed by: Solar eclipse of January 26, 1990
Tritos
- Preceded by: Lunar eclipse of February 21, 1970
- Followed by: Lunar eclipse of December 21, 1991
Lunar Saros 114
- Preceded by: Lunar eclipse of January 9, 1963
- Followed by: Lunar eclipse of January 31, 1999
Inex
- Preceded by: Lunar eclipse of February 11, 1952
- Followed by: Lunar eclipse of December 31, 2009
Triad
- Preceded by: Lunar eclipse of March 21, 1894
- Followed by: Lunar eclipse of November 21, 2067
Lunar eclipses of 1980–1984
Saros 114
Tritos series
Inex series
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 annular solar eclipses of Solar Saros 121.| January 16, 1972 | January 26, 1990 |