# December 2010 lunar eclipse

A total lunar eclipse occurred at the Moon’s descending node of orbit on Tuesday, December 21, 2010, with an umbral magnitude of 1.2576. A lunar eclipse occurs when the Moon moves into the Earth's shadow, causing the Moon to be darkened. A total lunar eclipse occurs when the Moon's near side entirely passes into the Earth's umbral shadow. 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. A total lunar eclipse can last up to nearly two hours, while a total solar eclipse lasts only a few minutes at any given place, because the Moon's shadow is smaller. Occurring about 4 days before apogee (on December 25, 2010, at 7:15 UTC), the Moon's apparent diameter was smaller.
This eclipse was notable in that it coincided with the date of the Winter solstice in the Northern Hemisphere and Summer solstice in the Southern Hemisphere. It was the first total lunar eclipse to occur on the day of the Northern Winter Solstice (Southern Summer Solstice) since 1638, and only the second in the Common Era.

## Visibility

The eclipse was completely visible over North America and the eastern Pacific Ocean, seen rising over east Asia and Australia and setting over South America, west Africa, and Europe.
| | Hourly motion shown right to left | The Moon's hourly motion across the Earth's shadow in the constellation of Taurus. |
| Visibility map |||

## Images

* These simulated views of the Earth from the center of the Moon during the lunar eclipse show where the eclipse is visible on Earth.

## Gallery

Progressions :
| Progression from São Paulo, Brazil ||
| Progression from Anchorage, Alaska ||
| Panorama showing the view from the site of the VLT ||
| Sequence from Toronto, Ontario, Canada (Sequence is in 15-minute increments, with 5-minute increments up until totality at 8:17 am UTC) | Progression from Toronto, Canada |
| From Jacksonville, Florida, 8:29 UTC - 10:06 UTC | From Easton, Pennsylvania |
Individual shots, sorted by time:
* From New York City, New York, 5:35 UTC
* From Arlington County, Virginia, ~7:30 UTC
* From New York City, New York, 7:38 UTC
* From Seattle, Washington, beginning of totality, 7:41 UTC
* From the Lower Mainland of British Columbia, Canada, 7:46 UTC
* From Miami, Florida, 7:52 UTC
* From Richardson, Texas, 7:53 UTC
* From Dover, Delaware, 7:54 UTC
* Lower Mainland of British Columbia, Canada during totality, 8:21 UTC
* From Toronto, Ontario, Canada, 8:26 UTC
* From Orlando, Florida, 8:28 UTC
* From Jacksonville, Florida, 8:30 UTC
* Amateur scientists observing eclipse in Villa Gesell, Argentina, 8:34 UTC
* From Tucson, Arizona, 8:44 UTC
* From Longjing District, Taichung, Taiwan at moonrise, 9:45 UTC
Animations:
* Animated Simulation
* Time-lapsed animation Miami, Florida

## Timing

In North America, the eclipse was visible in its entirety on 21 December 2010, from 12:27 a.m. to 6:06 a.m. Eastern Standard Time. In the Central Standard Time zone and west, the eclipse began the night of 20 December. Observers along South America's east coast missed the late stages of the eclipse because they occurred after moon-set.
Likewise much of Europe and Africa experienced moon-set while the eclipse was in progress. In Europe, only those observers in northern Scandinavia (including Iceland), Ireland and Britain could observe the entire event. For observers in eastern Asia the moon rose in eclipse. The eclipse was not visible from southern and eastern Africa, the Middle East or South Asia. In Japan and northeastern Asia, the eclipse's end was visible, with the moon rising at sunset. In the Philippines it was observable as a partial lunar eclipse just after sunset.
Predictions suggested that the total eclipse may appear unusually orange or red, as a result of the eruption of Mount Merapi in Indonesia on 26 October.
Local times of eclipse over North America :
| Event | HAST (UTC-10) | AKST (UTC−9) | PST (UTC−8) | MST (UTC−7) | CST (UTC−6) | EST (UTC−5) | AST (UTC−4) | UTC (UTC) |
| Start penumbral (P1) | 7:29 pm$^{(*)}$ | 8:29 pm$^{(*)}$ | 9:29 pm$^{(*)}$ | 10:29 pm$^{(*)}$ | 11:29 pm$^{(*)}$ | 12:29 am | 1:29 am | 5:29 am |
| Start umbral (U1) | 8:33 pm$^{(*)}$ | 9:33 pm$^{(*)}$ | 10:33 pm$^{(*)}$ | 11:33 pm$^{(*)}$ | 12:33 am | 1:33 am | 2:33 am | 6:33 am |
| Start total (U2) | 9:41 pm$^{(*)}$ | 10:41 pm$^{(*)}$ | 11:41 pm$^{(*)}$ | 12:41 am | 1:41 am | 2:41 am | 3:41 am | 7:41 am |
| Greatest eclipse | 10:17 pm$^{(*)}$ | 11:17 pm$^{(*)}$ | 12:17 am | 1:17 am | 2:17 am | 3:17 am | 4:17 am | 8:17 am |
| End total (U3) | 10:53 pm$^{(*)}$ | 11:53 pm$^{(*)}$ | 12:53 am | 1:53 am | 2:53 am | 3:53 am | 4:53 am | 8:53 am |
| End umbral (U4) | 12:01 am | 1:01 am | 2:01 am | 3:01 am | 4:01 am | 5:01 am | 6:01 am | 10:01 am |
| End penumbral (P4) | 1:04 am | 2:04 am | 3:04 am | 4:04 am | 5:04 am | 6:04 am | 7:04 am | 11:04 am |
| (*) before midnight on Monday night, 20 December |||||||||

## Eclipse details

Shown below is a table displaying details about this particular solar eclipse. It describes various parameters pertaining to this eclipse.
December 21, 2010 Lunar Eclipse Parameters :
| Parameter | Value |
| Penumbral Magnitude | 2.28215 |
| Umbral Magnitude | 1.25759 |
| Gamma | 0.32139 |
| Sun Right Ascension | 17h57m09.6s |
| Sun Declination | -23°26'09.9" |
| Sun Semi-Diameter | 16'15.5" |
| Sun Equatorial Horizontal Parallax | 08.9" |
| Moon Right Ascension | 05h57m17.3s |
| Moon Declination | +23°44'47.8" |
| Moon Semi-Diameter | 15'52.1" |
| Moon Equatorial Horizontal Parallax | 0°58'14.3" |
| ΔT | 66.4 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 December 2010–January 2011 :
| December 21 Descending node (full moon) | January 4 Ascending node (new moon) |
| Total lunar eclipse Lunar Saros 125 | Partial solar eclipse Solar Saros 151 |

## Related eclipses
### Eclipses in 2010

* An annular solar eclipse on January 15.
* A partial lunar eclipse on June 26.
* A total solar eclipse on July 11.
* A total lunar eclipse on December 21.

### Metonic

* Preceded by: Lunar eclipse of March 3, 2007
* Followed by: Lunar eclipse of October 8, 2014

### Tzolkinex

* Preceded by: Lunar eclipse of November 9, 2003
* Followed by: Lunar eclipse of January 31, 2018

### Half-Saros

* Preceded by: Solar eclipse of December 14, 2001
* Followed by: Solar eclipse of December 26, 2019

### Tritos

* Preceded by: Lunar eclipse of January 21, 2000
* Followed by: Lunar eclipse of November 19, 2021

### Lunar Saros 125

* Preceded by: Lunar eclipse of December 9, 1992
* Followed by: Lunar eclipse of December 31, 2028

### Inex

* Preceded by: Lunar eclipse of January 10, 1982
* Followed by: Lunar eclipse of November 30, 2039

### Triad

* Preceded by: Lunar eclipse of February 20, 1924
* Followed by: Lunar eclipse of October 21, 2097

### Lunar eclipses of 2009–2013

This eclipse is a member of a semester series. An eclipse in a semester series of lunar eclipses repeats approximately every 177 days and 4 hours (a semester) at alternating nodes of the Moon's orbit.
The penumbral lunar eclipses on February 9, 2009 and August 6, 2009 occur in the previous lunar year eclipse set, and the lunar eclipses on April 25, 2013 (partial) and October 18, 2013 (penumbral) occur in the next lunar year eclipse set.
Lunar eclipse series sets from 2009 to 2013 :
| Ascending node | Ascending node | Ascending node | Ascending node | Descending node | Descending node | Descending node | Descending node |
| Saros | Date Viewing | Type Chart | Gamma | Saros | 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 |

### Metonic series

The Metonic cycle repeats nearly exactly every 19 years and represents a Saros cycle plus one lunar year. Because it occurs on the same calendar date, the Earth's shadow will be in nearly the same location relative to the background stars.
| Ascending node | Descending node |
| 1991 Jun 27 - penumbral (110) 2010 Jun 26 - partial (120) 2029 Jun 26 - total (130) 2048 Jun 26 - partial (140) 2067 Jun 27 - penumbral (150) | 1991 Dec 21 - partial (115) 2010 Dec 21 - total (125) 2029 Dec 20 - total (135) 2048 Dec 20 - partial (145) |

### Saros 125

This eclipse is a part of Saros series 125, repeating every 18 years, 11 days, and containing 72 events. The series started with a penumbral lunar eclipse on July 17, 1163. It contains partial eclipses from January 17, 1470 through June 6, 1686; total eclipses from June 17, 1704 through March 19, 2155; and a second set of partial eclipses from March 29, 2173 through June 25, 2317. The series ends at member 72 as a penumbral eclipse on September 9, 2443.
The longest duration of totality was produced by member 37 at 100 minutes, 23 seconds on August 22, 1812. All eclipses in this series occur at the Moon’s descending node of orbit.
| Greatest | First | First | First | First |
| The greatest eclipse of the series occurred on 1812 Aug 22, lasting 100 minutes, 23 seconds. | Penumbral | Partial | Total | Central |
| The greatest eclipse of the series occurred on 1812 Aug 22, lasting 100 minutes, 23 seconds. | 1163 Jul 17 | 1470 Jan 17 | 1704 Jun 17 | 1758 Jul 20 |
| Last ||||
| The greatest eclipse of the series occurred on 1812 Aug 22, lasting 100 minutes, 23 seconds. | Central | Total | Partial | Penumbral |
| The greatest eclipse of the series occurred on 1812 Aug 22, lasting 100 minutes, 23 seconds. | 1920 Oct 27 | 2155 Mar 19 | 2317 Jun 25 | 2443 Sep 09 |
Eclipses are tabulated in three columns; every third eclipse in the same column is one exeligmos apart, so they all cast shadows over approximately the same parts of the Earth.
Series members 37–58 occur between 1801 and 2200: :
| 37 | 37 | 38 | 38 | 39 | 39 |
| 1812 Aug 22 | 1812 Aug 22 | 1830 Sep 02 | 1830 Sep 02 | 1848 Sep 13 | 1848 Sep 13 |
| 40 | 40 | 41 | 41 | 42 | 42 |
| 1866 Sep 24 | 1866 Sep 24 | 1884 Oct 04 | 1884 Oct 04 | 1902 Oct 17 | 1902 Oct 17 |
| 43 | 43 | 44 | 44 | 45 | 45 |
| 1920 Oct 27 | 1920 Oct 27 | 1938 Nov 07 | 1938 Nov 07 | 1956 Nov 18 | 1956 Nov 18 |
| 46 | 46 | 47 | 47 | 48 | 48 |
| 1974 Nov 29 | 1974 Nov 29 | 1992 Dec 09 | 1992 Dec 09 | 2010 Dec 21 | 2010 Dec 21 |
| 49 | 49 | 50 | 50 | 51 | 51 |
| 2028 Dec 31 | 2028 Dec 31 | 2047 Jan 12 | 2047 Jan 12 | 2065 Jan 22 | 2065 Jan 22 |
| 52 | 52 | 53 | 53 | 54 | 54 |
| 2083 Feb 02 | 2083 Feb 02 | 2101 Feb 14 | 2101 Feb 14 | 2119 Feb 25 | 2119 Feb 25 |
| 55 | 55 | 56 | 56 | 57 | 57 |
| 2137 Mar 07 | 2137 Mar 07 | 2155 Mar 19 | 2155 Mar 19 | 2173 Mar 29 | 2173 Mar 29 |
| 58 ||
| 2191 Apr 09 ||

### Tritos series

This eclipse is a part of a tritos cycle, repeating at alternating nodes every 135 synodic months (≈ 3986.63 days, or 11 years minus 1 month). Their appearance and longitude are irregular due to a lack of synchronization with the anomalistic month (period of perigee), but groupings of 3 tritos cycles (≈ 33 years minus 3 months) come close (≈ 434.044 anomalistic months), so eclipses are similar in these groupings.
Series members between 1801 and 2200 :
| 1803 Aug 03 (Saros 106) | 1803 Aug 03 (Saros 106) | 1814 Jul 02 (Saros 107) | 1814 Jul 02 (Saros 107) | 1825 Jun 01 (Saros 108) | 1825 Jun 01 (Saros 108) | 1836 May 01 (Saros 109) | 1836 May 01 (Saros 109) | 1847 Mar 31 (Saros 110) | 1847 Mar 31 (Saros 110) |
| 1858 Feb 27 (Saros 111) | 1858 Feb 27 (Saros 111) | 1869 Jan 28 (Saros 112) | 1869 Jan 28 (Saros 112) | 1879 Dec 28 (Saros 113) | 1879 Dec 28 (Saros 113) | 1890 Nov 26 (Saros 114) | 1890 Nov 26 (Saros 114) | 1901 Oct 27 (Saros 115) | 1901 Oct 27 (Saros 115) |
| 1912 Sep 26 (Saros 116) | 1912 Sep 26 (Saros 116) | 1923 Aug 26 (Saros 117) | 1923 Aug 26 (Saros 117) | 1934 Jul 26 (Saros 118) | 1934 Jul 26 (Saros 118) | 1945 Jun 25 (Saros 119) | 1945 Jun 25 (Saros 119) | 1956 May 24 (Saros 120) | 1956 May 24 (Saros 120) |
| 1967 Apr 24 (Saros 121) | 1967 Apr 24 (Saros 121) | 1978 Mar 24 (Saros 122) | 1978 Mar 24 (Saros 122) | 1989 Feb 20 (Saros 123) | 1989 Feb 20 (Saros 123) | 2000 Jan 21 (Saros 124) | 2000 Jan 21 (Saros 124) | 2010 Dec 21 (Saros 125) | 2010 Dec 21 (Saros 125) |
| 2021 Nov 19 (Saros 126) | 2021 Nov 19 (Saros 126) | 2032 Oct 18 (Saros 127) | 2032 Oct 18 (Saros 127) | 2043 Sep 19 (Saros 128) | 2043 Sep 19 (Saros 128) | 2054 Aug 18 (Saros 129) | 2054 Aug 18 (Saros 129) | 2065 Jul 17 (Saros 130) | 2065 Jul 17 (Saros 130) |
| 2076 Jun 17 (Saros 131) | 2076 Jun 17 (Saros 131) | 2087 May 17 (Saros 132) | 2087 May 17 (Saros 132) | 2098 Apr 15 (Saros 133) | 2098 Apr 15 (Saros 133) | 2109 Mar 17 (Saros 134) | 2109 Mar 17 (Saros 134) | 2120 Feb 14 (Saros 135) | 2120 Feb 14 (Saros 135) |
| 2131 Jan 13 (Saros 136) | 2131 Jan 13 (Saros 136) | 2141 Dec 13 (Saros 137) | 2141 Dec 13 (Saros 137) | 2152 Nov 12 (Saros 138) | 2152 Nov 12 (Saros 138) | 2163 Oct 12 (Saros 139) | 2163 Oct 12 (Saros 139) | 2174 Sep 11 (Saros 140) | 2174 Sep 11 (Saros 140) |
| 2185 Aug 11 (Saros 141) | 2185 Aug 11 (Saros 141) | 2196 Jul 10 (Saros 142) | 2196 Jul 10 (Saros 142) |

### Inex series

This eclipse is a part of the long period inex cycle, repeating at alternating nodes, every 358 synodic months (≈ 10,571.95 days, or 29 years minus 20 days). Their appearance and longitude are irregular due to a lack of synchronization with the anomalistic month (period of perigee). However, groupings of 3 inex cycles (≈ 87 years minus 2 months) comes close (≈ 1,151.02 anomalistic months), so eclipses are similar in these groupings.
Series members between 1801 and 2200 :
| 1808 May 10 (Saros 118) | 1808 May 10 (Saros 118) | 1837 Apr 20 (Saros 119) | 1837 Apr 20 (Saros 119) | 1866 Mar 31 (Saros 120) | 1866 Mar 31 (Saros 120) |
| 1895 Mar 11 (Saros 121) | 1895 Mar 11 (Saros 121) | 1924 Feb 20 (Saros 122) | 1924 Feb 20 (Saros 122) | 1953 Jan 29 (Saros 123) | 1953 Jan 29 (Saros 123) |
| 1982 Jan 09 (Saros 124) | 1982 Jan 09 (Saros 124) | 2010 Dec 21 (Saros 125) | 2010 Dec 21 (Saros 125) | 2039 Nov 30 (Saros 126) | 2039 Nov 30 (Saros 126) |
| 2068 Nov 09 (Saros 127) | 2068 Nov 09 (Saros 127) | 2097 Oct 21 (Saros 128) | 2097 Oct 21 (Saros 128) | 2126 Oct 01 (Saros 129) | 2126 Oct 01 (Saros 129) |
| 2155 Sep 11 (Saros 130) | 2155 Sep 11 (Saros 130) | 2184 Aug 21 (Saros 131) | 2184 Aug 21 (Saros 131) |

### Half-Saros cycle

A lunar eclipse will be preceded and followed by solar eclipses by 9 years and 5.5 days (a half saros). This lunar eclipse is related to two annular solar eclipses of Solar Saros 132.
| December 14, 2001 | December 26, 2019 |