May 1966 lunar eclipse
A penumbral lunar eclipse occurred at the Moon’s descending node of orbit on Wednesday, May 4, 1966, with an umbral magnitude of −0.0727. 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 2.75 days after perigee, the Moon's apparent diameter was larger.
Visibility
The eclipse was completely visible over Africa, Europe, the western half of Asia, and Antarctica, seen rising over South America and the Atlantic Ocean and setting over east Asia and Australia.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 | 0.91576 |
| Umbral Magnitude | −0.07272 |
| Gamma | 1.05536 |
| Sun Right Ascension | 02h45m54.8s |
| Sun Declination | +16°01'34.2" |
| Sun Semi-Diameter | 15'51.5" |
| Sun Equatorial Horizontal Parallax | 08.7" |
| Moon Right Ascension | 14h47m34.9s |
| Moon Declination | -15°04'18.1" |
| Moon Semi-Diameter | 16'02.6" |
| Moon Equatorial Horizontal Parallax | 0°58'52.9" |
| ΔT | 36.8 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.| May 4 Descending node | May 20 Ascending node |
| Penumbral lunar eclipse Lunar Saros 111 | Annular solar eclipse Solar Saros 137 |
Related eclipses
Eclipses in 1966
A penumbral lunar eclipse on May 4.- An annular solar eclipse on May 20.
- A penumbral lunar eclipse on October 29.
- A total solar eclipse on November 12.
Metonic
- Preceded by: Lunar eclipse of July 17, 1962
- Followed by: Lunar eclipse of February 21, 1970
Tzolkinex
- Preceded by: Lunar eclipse of March 24, 1959
- Followed by: Lunar eclipse of June 15, 1973
Half-Saros
- Preceded by: Solar eclipse of April 30, 1957
- Followed by: Solar eclipse of May 11, 1975
Tritos
- Preceded by: Lunar eclipse of June 5, 1955
- Followed by: Lunar eclipse of April 4, 1977
Lunar Saros 111
- Preceded by: Lunar eclipse of April 23, 1948
- Followed by: Lunar eclipse of May 15, 1984
Inex
- Preceded by: Lunar eclipse of May 25, 1937
- Followed by: Lunar eclipse of April 15, 1995
Triad
- Preceded by: Lunar eclipse of July 3, 1879
- Followed by: Lunar eclipse of March 4, 2053
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 solar eclipses of Solar Saros 118.| April 30, 1957 | May 11, 1975 |