A total lunar eclipse occurred at the Moon’s ascending node of orbit on Friday, April 22, 1921, with an umbral magnitude of 1.0678. A lunar eclipse occurs when the Moon moves into the Earth's shadow, causing the Moon to be darkened. A total lunar eclipse occurs when the Moon's near side entirely passes into the Earth's umbral shadow. 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. A total lunar eclipse can last up to nearly two hours, while a total solar eclipse lasts only a few minutes at any given place, because the Moon's shadow is smaller. Occurring only about 5.6 days after perigee (on April 16, 1921, at 16:10 UTC), the Moon's apparent diameter was larger.
This lunar eclipse was the third of an almost tetrad, with the others being on May 3, 1920 (total); October 27, 1920 (total); and October 16, 1921 (partial).
This was the first total lunar eclipse of Lunar Saros 130.
Visibility The eclipse was completely visible over much of North America and western South America, seen rising over northeast Asia and Australia and setting over eastern South America, western Europe, and west Africa.
Eclipse details Shown below is a table displaying details about this particular solar eclipse. It describes various parameters pertaining to this eclipse.
+April 22, 1921 Lunar Eclipse Parameters Parameter Value Penumbral Magnitude 2.08154 Umbral Magnitude 1.06782 Gamma 0.42693 Sun Right Ascension 01h57m53.3s Sun Declination +12°02'44.0" Sun Semi-Diameter 15'54.4" Sun Equatorial Horizontal Parallax 08.7" Moon Right Ascension 13h58m18.6s Moon Declination -11°38'56.5" Moon Semi-Diameter 15'41.5" Moon Equatorial Horizontal Parallax 0°57'35.3" ΔT 22.2 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 April 1921 April 8Descending node (new moon) April 22Ascending node (full moon) Annular solar eclipseSolar Saros 118 Total lunar eclipseLunar Saros 130
Related eclipses Eclipses in 1921 An annular solar eclipse on April 8. A total lunar eclipse on April 22. A total solar eclipse on October 1. A partial lunar eclipse on October 16.
Metonic Preceded by: Lunar eclipse of July 4, 1917 Followed by: Lunar eclipse of February 8, 1925
Tzolkinex Preceded by: Lunar eclipse of March 12, 1914 Followed by: Lunar eclipse of June 3, 1928
Half-Saros Preceded by: Solar eclipse of April 17, 1912 Followed by: Solar eclipse of April 28, 1930
Tritos Preceded by: Lunar eclipse of May 24, 1910 Followed by: Lunar eclipse of March 22, 1932
Lunar Saros 130 Preceded by: Lunar eclipse of April 12, 1903 Followed by: Lunar eclipse of May 3, 1939
Inex Preceded by: Lunar eclipse of May 11, 1892 Followed by: Lunar eclipse of April 2, 1950
Triad Preceded by: Lunar eclipse of June 21, 1834 Followed by: Lunar eclipse of February 21, 2008
Lunar eclipses of 1919–1922 This eclipse is a member of a semester series. An eclipse in a semester series of lunar eclipses repeats approximately every 177 days and 4 hours (a semester) at alternating nodes of the Moon's orbit.
The penumbral lunar eclipse on March 13, 1922 occurs in the next lunar year eclipse set.
Lunar eclipse series sets from 1919 to 1922 Ascending node Descending node Saros DateViewing TypeChart Gamma Saros DateViewing TypeChart Gamma 110 1919 May 15Penumbral −1.0820 115 1919 Nov 07Partial 0.9246 120 1920 May 03Total −0.3312 125 1920 Oct 27Total 0.2502 130 1921 Apr 22Total 0.4269 135 1921 Oct 16Partial −0.4902 140 1922 Apr 11Penumbral 1.1228 145 1922 Oct 06Penumbral −1.2348
Saros 130
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 annular solar eclipses of Solar Saros 137. April 17, 1912April 28, 1930
See also List of lunar eclipses List of 20th-century lunar eclipses
Notes
External links