April 1921 lunar eclipse

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, 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 ; October 27, 1920 ; and October 16, 1921.
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.

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 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 8 Descending node	April 22 Ascending node

Annular solar eclipse Solar Saros 118	Total lunar eclipse Lunar 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

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 at alternating nodes of the Moon's orbit.
The penumbral lunar eclipse on March 13, 1922 occurs in the next lunar year eclipse set.

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 annular solar eclipses of Solar Saros 137.

April 17, 1912	April 28, 1930