A penumbral lunar eclipse occurred at the Moon’s ascending node of orbit on Sunday, July 15, 1973, with an umbral magnitude of −0.9581. 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 3 days after apogee (on July 12, 1973, at 22:45 UTC), the Moon's apparent diameter was smaller.
This eclipse was the third of four lunar eclipses in 1973, with the others occurring on January 18 (penumbral), June 15 (penumbral), and December 10 (partial).
This was the first lunar eclipse of Saros series 148.
Visibility The eclipse was completely visible over Australia, western North America, and Antarctica, seen rising over east Asia and setting over central North America and western South America.
Eclipse details Shown below is a table displaying details about this particular solar eclipse. It describes various parameters pertaining to this eclipse.
+July 15, 1973 Lunar Eclipse Parameters Parameter Value Penumbral Magnitude 0.10468 Umbral Magnitude −0.95805 Gamma 1.51782 Sun Right Ascension 07h38m36.3s Sun Declination +21°30'35.7" Sun Semi-Diameter 15'44.1" Sun Equatorial Horizontal Parallax 08.7" Moon Right Ascension 19h37m04.9s Moon Declination -20°10'55.9" Moon Semi-Diameter 14'48.4" Moon Equatorial Horizontal Parallax 0°54'20.5" ΔT 43.9 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. The first and last eclipse in this sequence is separated by one synodic month.
+ Eclipse season of June–July 1973 June 15Ascending node (full moon) June 30Descending node (new moon) July 15Ascending node (full moon) Penumbral lunar eclipseLunar Saros 110 Total solar eclipseSolar Saros 136 Penumbral lunar eclipseLunar Saros 148
Related eclipses Eclipses in 1973 An annular solar eclipse on January 4. A penumbral lunar eclipse on January 18. A penumbral lunar eclipse on June 15. A total solar eclipse on June 30. A penumbral lunar eclipse on July 15. A partial lunar eclipse on December 10. An annular solar eclipse on December 24.
Metonic Preceded by: Lunar eclipse of September 25, 1969
Tzolkinex Followed by: Lunar eclipse of August 26, 1980
Half-Saros Preceded by: Solar eclipse of July 9, 1964 Followed by: Solar eclipse of July 20, 1982
Tritos Preceded by: Lunar eclipse of August 15, 1962 Followed by: Lunar eclipse of June 13, 1984
Lunar Saros 148 Followed by: Lunar eclipse of July 26, 1991
Inex Preceded by: Lunar eclipse of August 4, 1944 Followed by: Lunar eclipse of June 24, 2002
Triad Preceded by: Lunar eclipse of September 13, 1886
Lunar eclipses of 1969–1973
Saros 148
Tritos series
Series members between 1801 and 2060 1809 Oct 23(Saros 133) 1820 Sep 22(Saros 134) 1831 Aug 23(Saros 135) 1842 Jul 22(Saros 136) 1853 Jun 21(Saros 137) 1864 May 21(Saros 138) 1875 Apr 20(Saros 139) 1886 Mar 20(Saros 140) 1897 Feb 17(Saros 141) 1908 Jan 18(Saros 142) 1918 Dec 17(Saros 143) 1929 Nov 17(Saros 144) 1940 Oct 16(Saros 145) 1951 Sep 15(Saros 146) 1962 Aug 15(Saros 147) 1973 Jul 15(Saros 148) 1984 Jun 13(Saros 149) 2060 Nov 08(Saros 156)
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 partial solar eclipses of Solar Saros 155.
July 9, 1964July 20, 1982
See also List of lunar eclipses List of 20th-century lunar eclipses
Notes
External links