December 2009 lunar eclipse

Partial eclipse
Partiality as viewed from Munster, Ireland, 19:43 UTC
Date	December 31, 2009
Gamma	0.9765
Magnitude	0.0779
Saros cycle	115 (57 of 72)
Partiality	59 minutes, 58 seconds
Penumbral	251 minutes, 3 seconds
Contacts (UTC) P1 17:17:08 U1 18:52:43 Greatest 19:22:39 U4 19:52:41 P4 21:28:11
← August 2009 June 2010 →

A partial lunar eclipse occurred at the Moon’s descending node of orbit on Thursday, December 31, 2009,^[1] 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 January 1, 2010, at 15:30 UTC), the Moon's apparent diameter was larger.^[2]

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 December 31, 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.

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.^[3]

	Hourly motion shown right to left	The Moon's hourly motion across the Earth's shadow in the constellation of Gemini.
Visibility map

Progression from Degania A, Israel

• 
  Sheffield, England, 19:14 UTC
• 
  Qingdao, China, 19:16 UTC
• 
  Laguja, Estonia, 19:21 UTC
• 
  Beijing, China
  At maximum, 19:22 UTC
• 
  Tokyo, Japan, 19:32 UTC
• 
  Chennai, India, 19:33 UTC
• 
  Barcelona, Spain, 19:34 UTC
• 
  Athens, Greece, 19:34 UTC
• 
  Helsinki, Finland, 19:47 UTC
• 
  Nonthaburi, Thailand, 19:59 UTC
• 
  Belfort, France
  Combined images

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

December 31, 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

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 31 Descending node (full moon)	January 15 Ascending node (new moon)
Partial lunar eclipse Lunar Saros 115	Annular solar eclipse Solar Saros 141

• An annular solar eclipse on January 26.
• A penumbral lunar eclipse on February 9.
• A penumbral lunar eclipse on July 7.
• A total solar eclipse on July 22.
• A penumbral lunar eclipse on August 6.
• A partial lunar eclipse on December 31.

• Preceded by: Lunar eclipse of March 14, 2006
• Followed by: Lunar eclipse of October 18, 2013

• Preceded by: Lunar eclipse of November 20, 2002
• Followed by: Lunar eclipse of February 11, 2017

• Preceded by: Solar eclipse of December 25, 2000
• Followed by: Solar eclipse of January 6, 2019

• Preceded by: Lunar eclipse of January 31, 1999
• Followed by: Lunar eclipse of November 30, 2020

• Preceded by: Lunar eclipse of December 21, 1991
• Followed by: Lunar eclipse of January 12, 2028

• Preceded by: Lunar eclipse of January 20, 1981
• Followed by: Lunar eclipse of December 11, 2038

• Preceded by: Lunar eclipse of March 3, 1923
• Followed by: Lunar eclipse of October 31, 2096

This eclipse is the one of four lunar eclipses in a short-lived series. The lunar year series repeats after 12 lunations or 354 days (Shifting back about 10 days in sequential years). Because of the date shift, the Earth's shadow will be about 11 degrees west in sequential events.

Lunar eclipse series sets from 2009–2013
Ascending node					Descending node
Saros # Photo	Date Viewing	Type chart	Gamma		Saros # Photo	Date Viewing	Type chart	Gamma
110	2009 Jul 07	penumbral	−1.4916		115	2009 Dec 31	partial	0.9766
120	2010 Jun 26	partial	−0.7091		125	2010 Dec 21	total	0.3214
130	2011 Jun 15	total	0.0897		135	2011 Dec 10	total	−0.3882
140	2012 Jun 04	partial	0.8248		145	2012 Nov 28	penumbral	−1.0869
150	2013 May 25	penumbral	1.5351
Last set	2009 Aug 06				Last set	2009 Feb 9
Next set	2013 Apr 25				Next set	2013 Oct 18

It was part of Saros series 115.

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 partial solar eclipses of Solar Saros 122.

December 25, 2000	January 6, 2019

• List of lunar eclipses
• List of 21st-century lunar eclipses
• File:2009-12-31 Lunar Eclipse Sketch.gif Chart

• 2009 Dec 31 chart: Eclipse Predictions by Fred Espenak, NASA/GSFC
• Hermit eclipse: 2009-12-31
• [1] Eclipse enthusiasts in Europe, Africa, Australia and Asia can celebrate New Year's Eve by observing a partial lunar eclipse on December 31, 2009. The event's duration will be about four hours.