April 1931 lunar eclipse

April 1931 lunar eclipse
Total eclipse
The Moon's hourly motion shown right to left
DateApril 2, 1931
Gamma0.2043
Magnitude1.5021
Saros cycle121 (51 of 84)
Totality89 minutes, 36 seconds
Partiality207 minutes, 50 seconds
Penumbral317 minutes, 56 seconds
Contacts (UTC)
P117:28:34
U118:23:35
U219:22:43
Greatest20:07:31
U320:52:19
U421:51:25
P422:46:30

A total lunar eclipse occurred at the Moon’s descending node of orbit on Thursday, April 2, 1931,[1] with an umbral magnitude of 1.5021. 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 24 hours after perigee (on April 1, 1931, at 22:05 UTC), the Moon's apparent diameter was larger.[2]

Visibility

The eclipse was completely visible over central and east Africa, eastern Europe, and much of Asia, seen rising over west Africa, western Europe, and much of South America and setting over east and northeast Asia and Australia.[3]

Eclipse details

Shown below is a table displaying details about this particular solar eclipse. It describes various parameters pertaining to this eclipse.[4]

April 2, 1931 Lunar Eclipse Parameters
Parameter Value
Penumbral Magnitude 2.46366
Umbral Magnitude 1.50213
Gamma 0.20432
Sun Right Ascension 00h44m34.7s
Sun Declination +04°47'34.2"
Sun Semi-Diameter 15'59.8"
Sun Equatorial Horizontal Parallax 08.8"
Moon Right Ascension 12h44m58.7s
Moon Declination -04°36'37.3"
Moon Semi-Diameter 16'38.2"
Moon Equatorial Horizontal Parallax 1°01'03.6"
ΔT 24.0 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 1931
April 2
Descending node (full moon)
April 18
Ascending node (new moon)
Total lunar eclipse
Lunar Saros 121
Partial solar eclipse
Solar Saros 147

Eclipses in 1931

Metonic

Tzolkinex

Half-Saros

Tritos

Lunar Saros 121

Inex

Triad

Lunar eclipses of 1930–1933

Lunar eclipse series sets from 1930–1933
Descending node   Ascending node
Saros Date
viewing
Type
chart
Saros Date
viewing
Type
chart
111 1930 Apr 13
Partial
116 1930 Oct 07
Partial
121 1931 Apr 02
Total
126 1931 Sep 26
Total
131 1932 Mar 22
Partial
136 1932 Sep 14
Partial
141 1933 Mar 12
Penumbral
146 1933 Sep 04
Penumbral

Saros 121

Half-Saros cycle

A lunar eclipse will be preceded and followed by solar eclipses by 9 years and 5.5 days (a half saros).[5] This lunar eclipse is related to two total solar eclipses of Solar Saros 128.

March 28, 1922 April 7, 1940

See also

References

  1. ^ "April 2–3, 1931 Total Lunar Eclipse (Blood Moon)". timeanddate. Retrieved 16 December 2024.
  2. ^ "Moon Distances for London, United Kingdom, England". timeanddate. Retrieved 16 December 2024.
  3. ^ "Total Lunar Eclipse of 1931 Apr 02" (PDF). NASA. Retrieved 16 December 2024.
  4. ^ "Total Lunar Eclipse of 1931 Apr 02". EclipseWise.com. Retrieved 16 December 2024.
  5. ^ Mathematical Astronomy Morsels, Jean Meeus, p.110, Chapter 18, The half-saros