A partial lunar eclipse occurred at the Moon’s descending node of orbit on Thursday, 31 December 2009, with an umbral magnitude of 0.0779. 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 only about 20 hours before perigee (on 1 January 2010, at 15:30 UTC), the Moon's apparent diameter was larger.
This eclipse was the last of four lunar eclipses in 2009, with the others occurring on February 9 (penumbral), July 7 (penumbral), and August 6 (penumbral).
This lunar eclipse was also notable, because it occurred during a blue moon (a second full moon in December) and was near perigee (making it a supermoon). The next eclipse on New Year's Eve and blue moon will occur on 31 December 2028.
Only a small portion of the Moon entered the Earth's umbral shadow, but there was a distinct darkening visible over the Moon's southern surface at greatest eclipse.
Visibility The eclipse was completely visible over Europe, Asia, and much of Africa, seen rising over eastern North America and setting over Australia and the Pacific Ocean.
Hourly motion shown right to leftThe Moon's hourly motion across the Earth's shadow in the constellation of Gemini. Visibility map
Images
Gallery Progression from Degania A, Israel
Eclipse details Shown below is a table displaying details about this particular solar eclipse. It describes various parameters pertaining to this eclipse.
+31 December 2009 Lunar Eclipse Parameters Parameter Value Penumbral Magnitude 1.05719 Umbral Magnitude 0.07793 Gamma 0.97660 Sun Right Ascension 18h44m37.2s Sun Declination -23°02'33.1" Sun Semi-Diameter 16'15.9" Sun Equatorial Horizontal Parallax 08.9" Moon Right Ascension 06h45m22.4s Moon Declination +24°01'10.3" Moon Semi-Diameter 16'36.6" Moon Equatorial Horizontal Parallax 1°00'57.6" ΔT 66.1 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 December 2009–January 2010 December 31Descending node (full moon) 15 JanuaryAscending node (new moon) Partial lunar eclipseLunar Saros 115 Annular solar eclipseSolar Saros 141
Related eclipses Eclipses in 2009 An annular solar eclipse on 26 January. A penumbral lunar eclipse on 9 February. A penumbral lunar eclipse on 7 July. A total solar eclipse on 22 July. A penumbral lunar eclipse on 6 August. A partial lunar eclipse on 31 December.
Metonic Preceded by: Lunar eclipse of 14 March 2006 Followed by: Lunar eclipse of 18 October 2013
Tzolkinex Preceded by: Lunar eclipse of 20 November 2002 Followed by: Lunar eclipse of 11 February 2017
Half-Saros Preceded by: Solar eclipse of 25 December 2000 Followed by: Solar eclipse of 6 January 2019
Tritos Preceded by: Lunar eclipse of 31 January 1999 Followed by: Lunar eclipse of 30 November 2020
Lunar Saros 115 Preceded by: Lunar eclipse of 21 December 1991 Followed by: Lunar eclipse of 12 January 2028
Inex Preceded by: Lunar eclipse of 20 January 1981 Followed by: Lunar eclipse of 11 December 2038
Triad Preceded by: Lunar eclipse of 3 March 1923 Followed by: Lunar eclipse of 31 October 2096
Lunar eclipses of 2009–2013
Saros 115
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 partial solar eclipses of Solar Saros 122. 25 December 20006 January 2019
See also List of lunar eclipses List of 21st-century lunar eclipses :File:2009-12-31 Lunar Eclipse Sketch.gif Chart
References
External links
Hermit eclipse: 2009-12-31 Eclipse enthusiasts in Europe, Africa, Australia and Asia can celebrate New Year's Eve by observing a partial lunar eclipse on 31 December 2009. The event's duration will be about four hours.