A partial lunar eclipse occurred at the Moon’s descending node of orbit on Saturday, October 28, 1939, with an umbral magnitude of 0.9876. 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 5.3 days after apogee (on October 23, 1939, at 0:05 UTC), the Moon's apparent diameter was smaller.
This lunar eclipse was the last of an almost tetrad, with the others being on May 14, 1938 (total); November 7, 1938 (total); and May 3, 1939 (total).
This was the last partial lunar eclipse of the first set of partial eclipses in Lunar Saros 135 as well as the largest partial lunar eclipse of the 20th century.
Visibility The eclipse was completely visible over North America and western South America, seen rising over northeast Asia and eastern Australia and setting over eastern South America, west and central Africa, and Europe.
Eclipse details Shown below is a table describing various parameters pertaining to this eclipse.
+October 28, 1939 Lunar Eclipse Parameters Parameter Value Penumbral Magnitude 2.04769 Umbral Magnitude 0.98764 Gamma −0.45812 Sun Right Ascension 14h06m46.1s Sun Declination -12°50'04.8" Sun Semi-Diameter 16'05.9" Sun Equatorial Horizontal Parallax 08.9" Moon Right Ascension 02h07m11.5s Moon Declination +12°25'18.8" Moon Semi-Diameter 15'11.2" Moon Equatorial Horizontal Parallax 0°55'44.2" ΔT 24.4 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 October 1939 October 12Ascending node (new moon) October 28Descending node (full moon) Total solar eclipseSolar Saros 123 Partial lunar eclipseLunar Saros 135
Related eclipses Eclipses in 1939 An annular solar eclipse on April 19. A total lunar eclipse on May 3. A total solar eclipse on October 12. A partial lunar eclipse on October 28.
Metonic Preceded by: Lunar eclipse of January 8, 1936 Followed by: Lunar eclipse of August 15, 1943
Tzolkinex Preceded by: Lunar eclipse of September 14, 1932 Followed by: Lunar eclipse of December 8, 1946
Half-Saros Preceded by: Solar eclipse of October 21, 1930 Followed by: Solar eclipse of November 1, 1948
Tritos Preceded by: Lunar eclipse of November 27, 1928 Followed by: Lunar eclipse of September 26, 1950
Lunar Saros 135 Preceded by: Lunar eclipse of October 16, 1921 Followed by: Lunar eclipse of November 7, 1957
Inex Preceded by: Lunar eclipse of November 17, 1910 Followed by: Lunar eclipse of October 6, 1968
Triad Preceded by: Lunar eclipse of December 26, 1852 Followed by: Lunar eclipse of August 28, 2026
Lunar eclipses of 1937–1940
Saros 135
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 142. October 21, 1930November 1, 1948
See also List of lunar eclipses List of 20th-century lunar eclipses
Notes
External links