A penumbral lunar eclipse will occur at the Moon’s ascending node of orbit on Monday, April 22, 1940,[1] with an umbral magnitude of −0.0945. 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 2.7 days after perigee (on April 20, 1940, at 20:20 UTC), the Moon's apparent diameter was larger.[2]
| Penumbral eclipse | |||||||||
 The Moon's hourly motion shown right to left | |||||||||
| Date | April 22, 1940 | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Gamma | 1.0741 | ||||||||
| Magnitude | −0.0945 | ||||||||
| Saros cycle | 140 (21 of 80) | ||||||||
| Penumbral | 232 minutes, 31 seconds | ||||||||
| |||||||||
Visibility
editThe eclipse was completely visible over much of North America, South America, west Africa, and Antarctica, seen rising over northwestern North America and the central Pacific Ocean and setting over Africa, Europe, and the Middle East.[3]
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Eclipse details
editShown below is a table displaying details about this particular solar eclipse. It describes various parameters pertaining to this eclipse.[4]
| Parameter | Value |
|---|---|
| Penumbral Magnitude | 0.86836 |
| Umbral Magnitude | −0.09446 |
| Gamma | 1.07414 |
| Sun Right Ascension | 01h58m53.2s |
| Sun Declination | 12°08'03.3" |
| Sun Semi-Diameter | 15'54.5" |
| Sun Equatorial Horizontal Parallax | 08.7" |
| Moon Right Ascension | 14h00m00.5s |
| Moon Declination | -11°05'02.6" |
| Moon Semi-Diameter | 16'31.3" |
| Moon Equatorial Horizontal Parallax | 1°00'38.2" |
| ΔT | 24.5 s |
Eclipse season
editThis 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. The first and last eclipse in this sequence is separated by one synodic month.
| March 23 Ascending node (full moon) |
April 7 Descending node (new moon) |
April 22 Ascending node (full moon) |
|---|---|---|
 |
 |
|
| Penumbral lunar eclipse Lunar Saros 102 |
Annular solar eclipse Solar Saros 128 |
Penumbral lunar eclipse Lunar Saros 140 |
Related eclipses
editEclipses in 1940
edit- A penumbral lunar eclipse on March 23.
- An annular solar eclipse on April 7.
- A penumbral lunar eclipse on April 22.
- A total solar eclipse on October 1.
- A penumbral lunar eclipse on October 16.
Metonic
edit- Preceded by: Lunar eclipse of July 4, 1936
- Followed by: Lunar eclipse of February 9, 1944
Tzolkinex
edit- Preceded by: Lunar eclipse of March 12, 1933
- Followed by: Lunar eclipse of June 3, 1947
Half-Saros
edit- Preceded by: Solar eclipse of April 18, 1931
- Followed by: Solar eclipse of April 28, 1949
Tritos
edit- Preceded by: Lunar eclipse of May 23, 1929
- Followed by: Lunar eclipse of March 23, 1951
Lunar Saros 140
edit- Preceded by: Lunar eclipse of April 11, 1922
- Followed by: Lunar eclipse of May 3, 1958
Inex
edit- Preceded by: Lunar eclipse of May 13, 1911
- Followed by: Lunar eclipse of April 2, 1969
Triad
edit- Preceded by: Lunar eclipse of June 21, 1853
- Followed by: Lunar eclipse of February 20, 2027
Lunar eclipses of 1937–1940
edit| Ascending node | Descending node | |||||
|---|---|---|---|---|---|---|
| Saros | Date viewing |
Type chart |
Saros | Date viewing |
Type chart | |
| 110 | 1937 May 25
|
Penumbral
|
115 | 1937 Nov 18
|
Partial
| |
| 120 | 1938 May 14
|
Total
|
125 | 1938 Nov 07
|
Total
| |
| 130 | 1939 May 03
|
Total
|
135 | 1939 Oct 28
|
Partial
| |
| 140 | 1940 Apr 22
|
Penumbral
|
145 | 1940 Oct 16
|
Penumbral
| |
Saros 140
editIt was part of Saros series 140.
Half-Saros cycle
editA 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 partial solar eclipses of Solar Saros 147.
| April 18, 1931 | April 28, 1949 |
|---|---|
|
|
See also
editNotes
edit- ^ "April 21–22, 1940 Penumbral Lunar Eclipse". timeanddate. Retrieved 18 December 2024.
- ^ "Moon Distances for London, United Kingdom, England". timeanddate. Retrieved 18 December 2024.
- ^ "Penumbral Lunar Eclipse of 1940 Apr 22" (PDF). NASA. Retrieved 18 December 2024.
- ^ "Penumbral Lunar Eclipse of 1940 Apr 22". EclipseWise.com. Retrieved 18 December 2024.
- ^ Mathematical Astronomy Morsels, Jean Meeus, p.110, Chapter 18, The half-saros
External links
edit- 1940 Apr 22 chart Eclipse Predictions by Fred Espenak, NASA/GSFC
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