A partial lunar eclipse occurred at the Moon’s descending node of orbit on Friday, July 17, 1981, with an umbral magnitude of 0.5486. 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 5.4 days after apogee (on July 11, 1981, at 18:35 UTC), the Moon's apparent diameter was smaller.
Visibility The eclipse was completely visible over central and eastern North America, South America, and Antarctica, seen rising over western North America and the central Pacific Ocean and setting over much of Europe, Africa, 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.
+July 17, 1981 Lunar Eclipse Parameters Parameter Value Penumbral Magnitude 1.58223 Umbral Magnitude 0.54860 Gamma 0.70454 Sun Right Ascension 07h45m44.1s Sun Declination +21°13'06.1" Sun Semi-Diameter 15'44.2" Sun Equatorial Horizontal Parallax 08.7" Moon Right Ascension 19h45m30.8s Moon Declination -20°33'51.6" Moon Semi-Diameter 15'13.5" Moon Equatorial Horizontal Parallax 0°55'52.6" ΔT 51.9 s
Eclipse season
This eclipse is part of an eclipse season, a period, roughly every six months, when eclipses occur. Only two (or occasionally three) eclipse seasons occur each year, and each season lasts about 35 days and repeats just short of six months (173 days) 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.
+ Eclipse season of July 1981 July 17Descending node (full moon) July 31Ascending node (new moon) Partial lunar eclipseLunar Saros 119 Total solar eclipseSolar Saros 145
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 September 27, 1977 Followed by: Lunar eclipse of May 4, 1985
Tzolkinex Preceded by: Lunar eclipse of June 4, 1974 Followed by: Lunar eclipse of August 27, 1988
Half-Saros Preceded by: Solar eclipse of July 10, 1972 Followed by: Solar eclipse of July 22, 1990
Tritos Preceded by: Lunar eclipse of August 17, 1970 Followed by: Lunar eclipse of June 15, 1992
Lunar Saros 119 Preceded by: Lunar eclipse of July 6, 1963 Followed by: Lunar eclipse of July 28, 1999
Inex Preceded by: Lunar eclipse of August 5, 1952 Followed by: Lunar eclipse of June 26, 2010
Triad Preceded by: Lunar eclipse of September 15, 1894 Followed by: Lunar eclipse of May 17, 2068
Lunar eclipses of 1980–1984
Saros 119
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 (a half saros).Mathematical Astronomy Morsels, Jean Meeus, p.110, Chapter 18, The half-saros This lunar eclipse is related to two total solar eclipses of Solar Saros 126. July 10, 1972July 22, 1990
See also List of lunar eclipses List of 20th-century lunar eclipses
Notes
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