January 1991 lunar eclipse
A penumbral lunar eclipse occurred at the Moon’s descending node of orbit on Wednesday, January 30, 1991, with an umbral magnitude of −0.1106. 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 1.9 days after perigee, the Moon's apparent diameter was larger.
This eclipse was the first of four lunar eclipses in 1991, with the others occurring on June 27, July 26, and December 21.
Visibility
The eclipse was completely visible over North and South America, seen rising over northeast Asia and the central Pacific Ocean and setting over much of Africa and 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 | 0.88079 |
| Umbral Magnitude | −0.11060 |
| Gamma | −1.07522 |
| Sun Right Ascension | 20h49m07.1s |
| Sun Declination | -17°47'12.6" |
| Sun Semi-Diameter | 16'14.2" |
| Sun Equatorial Horizontal Parallax | 08.9" |
| Moon Right Ascension | 08h47m30.0s |
| Moon Declination | +16°46'53.1" |
| Moon Semi-Diameter | 16'22.7" |
| Moon Equatorial Horizontal Parallax | 1°00'06.5" |
| ΔT | 57.6 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 15 Ascending node | January 30 Descending node |
| Annular solar eclipse Solar Saros 131 | Penumbral lunar eclipse Lunar Saros 143 |
Related eclipses
Eclipses in 1991
- An annular solar eclipse on January 15.A penumbral lunar eclipse on January 30.
- A penumbral lunar eclipse on June 27.
- A total solar eclipse on July 11.
- A penumbral lunar eclipse on July 26.
- A partial lunar eclipse on December 21.
Metonic
- Preceded by: Lunar eclipse of April 14, 1987
- Followed by: Lunar eclipse of November 18, 1994
Tzolkinex
- Preceded by: Lunar eclipse of December 20, 1983
- Followed by: Lunar eclipse of March 13, 1998
Half-Saros
- Preceded by: Solar eclipse of January 25, 1982
- Followed by: Solar eclipse of February 5, 2000
Tritos
- Preceded by: Lunar eclipse of March 1, 1980
- Followed by: Lunar eclipse of December 30, 2001
Lunar Saros 143
- Preceded by: Lunar eclipse of January 18, 1973
- Followed by: Lunar eclipse of February 9, 2009
Inex
- Preceded by: Lunar eclipse of February 19, 1962
- Followed by: Lunar eclipse of January 10, 2020
Triad
- Preceded by: Lunar eclipse of March 31, 1904
- Followed by: Lunar eclipse of November 29, 2077
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 25, 1982 | February 5, 2000 |