April 1977 lunar eclipse
A partial lunar eclipse occurred at the Moon’s ascending node of orbit on Monday, April 4, 1977, with an umbral magnitude of 0.1929. 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 about 1.7 days before perigee, the Moon's apparent diameter was larger.
Visibility
The eclipse was completely visible over much of North America, South America, and west Africa, seen rising over western North America and the central Pacific Ocean and setting over Africa, Europe and the Middle East.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 | 1.16570 |
| Umbral Magnitude | 0.19289 |
| Gamma | −0.91483 |
| Sun Right Ascension | 00h52m35.5s |
| Sun Declination | +05°37'56.4" |
| Sun Semi-Diameter | 15'59.4" |
| Sun Equatorial Horizontal Parallax | 08.8" |
| Moon Right Ascension | 12h51m29.8s |
| Moon Declination | -06°30'38.9" |
| Moon Semi-Diameter | 16'26.2" |
| Moon Equatorial Horizontal Parallax | 1°00'19.6" |
| ΔT | 47.8 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.| April 4 Ascending node | April 18 Descending node |
| Partial lunar eclipse Lunar Saros 112 | Annular solar eclipse Solar Saros 138 |
Related eclipses
Eclipses in 1977
- A partial lunar eclipse on April 4.
- An annular solar eclipse on April 18.
- A penumbral lunar eclipse on September 27.
- A total solar eclipse on October 12.
Metonic
- Preceded by: Lunar eclipse of June 15, 1973
- Followed by: Lunar eclipse of January 20, 1981
Tzolkinex
- Preceded by: Lunar eclipse of February 21, 1970
- Followed by: Lunar eclipse of May 15, 1984
Half-Saros
- Preceded by: Solar eclipse of March 28, 1968
- Followed by: Solar eclipse of April 9, 1986
Tritos
- Preceded by: Lunar eclipse of May 4, 1966
- Followed by: Lunar eclipse of March 3, 1988
Lunar Saros 112
- Preceded by: Lunar eclipse of March 24, 1959
- Followed by: Lunar eclipse of April 15, 1995
Inex
- Preceded by: Lunar eclipse of April 23, 1948
- Followed by: Lunar eclipse of March 14, 2006
Triad
- Preceded by: Lunar eclipse of June 3, 1890
- Followed by: Lunar eclipse of February 2, 2064
Lunar eclipses of 1977–1980
Saros 112
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 partial solar eclipses of Solar Saros 119.| March 28, 1968 | April 9, 1986 |