Solar eclipse of December 4, 2021

A total solar eclipse occurred at the Moon’s descending node of orbit on Saturday, December 4, 2021,^[1][2][3][4] with a magnitude of 1.0367. A total solar eclipse occurs when the Moon's apparent diameter is larger than the Sun's and the apparent path of the Sun and Moon intersect, blocking all direct sunlight and turning daylight into darkness; the Sun appears to be black with a halo around it. Totality occurs in a narrow path across Earth's surface, with the partial solar eclipse visible over a surrounding region thousands of kilometres wide. Occurring about 2.5 hours before perigee (on December 4, 2021, at 10:00 UTC), the Moon's apparent diameter was larger.^[5]

Solar eclipse of December 4, 2021

Total eclipse
Map
Gamma	−0.9526
Magnitude	1.0367
Maximum eclipse
Duration	114 s (1 min 54 s)
Coordinates	76.8°S 46.2°W / -76.8; -46.2
Max. width of band	419 km (260 mi)
Times (UTC)
Greatest eclipse	7:34:38
References
Saros	152 (13 of 70)
Catalog # (SE5000)	9556
← June 10, 2021 April 30, 2022 →

This eclipse was unusual as the path of the total eclipse moved from east to west across West Antarctica, while most eclipse paths move from west to east. This reversal is only possible in polar regions. Its path across Antarctica crossed near Berkner Island, traversed an arc over the continent and passed over Shepard Island.^[6][7] A partial eclipse was visible for parts of Southern Africa, Antarctica, and Tasmania.

Images

• 
  Animated path
• 
  NASA's DSCOVR Satellite photo
• 
  As observed by the Royal Navy (HMS Protector) off South Georgia

Eclipse details

Shown below are two tables displaying details about this particular solar eclipse. The first table outlines times at which the moon's penumbra or umbra attains the specific parameter, and the second table describes various other parameters pertaining to this eclipse.^[8]

December 4, 2021 Solar Eclipse Times

Event	Time (UTC)
First Penumbral External Contact	2021 December 04 at 05:30:26.5 UTC
First Umbral External Contact	2021 December 04 at 07:01:16.7 UTC
First Central Line	2021 December 04 at 07:04:03.2 UTC
First Umbral Internal Contact	2021 December 04 at 07:07:04.8 UTC
Greatest Eclipse	2021 December 04 at 07:34:37.9 UTC
Greatest Duration	2021 December 04 at 07:34:40.1 UTC
Ecliptic Conjunction	2021 December 04 at 07:44:11.1 UTC
Equatorial Conjunction	2021 December 04 at 07:57:20.3 UTC
Last Umbral Internal Contact	2021 December 04 at 08:01:55.8 UTC
Last Central Line	2021 December 04 at 08:04:57.6 UTC
Last Umbral External Contact	2021 December 04 at 08:07:44.3 UTC
Last Penumbral External Contact	2021 December 04 at 09:38:39.3 UTC

December 4, 2021 Solar Eclipse Parameters

Parameter	Value
Eclipse Magnitude	1.03673
Eclipse Obscuration	1.07481
Gamma	−0.95261
Sun Right Ascension	16h43m32.4s
Sun Declination	-22°16'29.4"
Sun Semi-Diameter	16'13.6"
Sun Equatorial Horizontal Parallax	08.9"
Moon Right Ascension	16h42m35.0s
Moon Declination	-23°13'22.3"
Moon Semi-Diameter	16'44.7"
Moon Equatorial Horizontal Parallax	1°01'27.3"
ΔT	70.6 s

Eclipse season

See also: Eclipse cycle

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 November–December 2021

November 19 Ascending node (full moon)	December 4 Descending node (new moon)
Partial lunar eclipse Lunar Saros 126	Total solar eclipse Solar Saros 152

Related eclipses

Eclipses in 2021

• A total lunar eclipse on May 26.^[9]
• An annular solar eclipse on June 10.
• A partial lunar eclipse on November 19.
• A total solar eclipse on December 4.

Metonic

• Preceded by: Solar eclipse of February 15, 2018
• Followed by: Solar eclipse of September 21, 2025

Tzolkinex

• Preceded by: Solar eclipse of October 23, 2014
• Followed by: Solar eclipse of January 14, 2029

Half-Saros

• Preceded by: Lunar eclipse of November 28, 2012
• Followed by: Lunar eclipse of December 9, 2030

Tritos

• Preceded by: Solar eclipse of January 4, 2011
• Followed by: Solar eclipse of November 3, 2032

Solar Saros 152

• Preceded by: Solar eclipse of November 23, 2003
• Followed by: Solar eclipse of December 15, 2039

Inex

• Preceded by: Solar eclipse of December 24, 1992
• Followed by: Solar eclipse of November 14, 2050

Triad

• Preceded by: Solar eclipse of February 3, 1935
• Followed by: Solar eclipse of October 5, 2108

Solar eclipses of 2018–2021

This eclipse is a member of a semester series. An eclipse in a semester series of solar eclipses repeats approximately every 177 days and 4 hours (a semester) at alternating nodes of the Moon's orbit.^[10]

The partial solar eclipses on February 15, 2018 and August 11, 2018 occur in the previous lunar year eclipse set.

Solar eclipse series sets from 2018 to 2021
Ascending node				Descending node
Saros	Map	Gamma		Saros	Map	Gamma
117 Partial in Melbourne, Australia	July 13, 2018 Partial	−1.35423		122 Partial in Nakhodka, Russia	January 6, 2019 Partial	1.14174
127 Totality in La Serena, Chile	July 2, 2019 Total	−0.64656		132 Annularity in Jaffna, Sri Lanka	December 26, 2019 Annular	0.41351
137 Annularity in Beigang, Yunlin, Taiwan	June 21, 2020 Annular	0.12090		142 Totality in Gorbea, Chile	December 14, 2020 Total	−0.29394
147 Partial in Halifax, Canada	June 10, 2021 Annular	0.91516		152 From HMS Protector off South Georgia	December 4, 2021 Total	−0.95261

Saros 152

This eclipse is a part of Saros series 152, repeating every 18 years, 11 days, and containing 70 events. The series started with a partial solar eclipse on July 26, 1805. It contains total eclipses from November 2, 1967 through September 14, 2490; hybrid eclipses from September 26, 2508 through October 17, 2544; and annular eclipses from October 29, 2562 through June 16, 2941. The series ends at member 70 as a partial eclipse on August 20, 3049. Its 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.

The longest duration of totality will be produced by member 30 at 5 minutes, 16 seconds on June 9, 2328, and the longest duration of annularity will be produced by member 53 at 5 minutes, 20 seconds on February 16, 2743. All eclipses in this series occur at the Moon’s descending node of orbit.^[11]

Series members 1–22 occur between 1805 and 2200:
1	2	3
July 26, 1805	August 6, 1823	August 16, 1841
4	5	6
August 28, 1859	September 7, 1877	September 18, 1895
7	8	9
September 30, 1913	October 11, 1931	October 21, 1949
10	11	12
November 2, 1967	November 12, 1985	November 23, 2003
13	14	15
December 4, 2021	December 15, 2039	December 26, 2057
16	17	18
January 6, 2076	January 16, 2094	January 29, 2112
19	20	21
February 8, 2130	February 19, 2148	March 2, 2166
22
March 12, 2184

Metonic series

The metonic series repeats eclipses every 19 years (6939.69 days), lasting about 5 cycles. Eclipses occur in nearly the same calendar date. In addition, the octon subseries repeats 1/5 of that or every 3.8 years (1387.94 days). All eclipses in this table occur at the Moon's descending node.

21 eclipse events between July 11, 1953 and July 11, 2029
July 10–11	April 29–30	February 15–16	December 4	September 21–23
116	118	120	122	124
July 11, 1953	April 30, 1957	February 15, 1961	December 4, 1964	September 22, 1968
126	128	130	132	134
July 10, 1972	April 29, 1976	February 16, 1980	December 4, 1983	September 23, 1987
136	138	140	142	144
July 11, 1991	April 29, 1995	February 16, 1999	December 4, 2002	September 22, 2006
146	148	150	152	154
July 11, 2010	April 29, 2014	February 15, 2018	December 4, 2021	September 21, 2025
156
July 11, 2029

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 2087
August 17, 1803 (Saros 132)	July 17, 1814 (Saros 133)	June 16, 1825 (Saros 134)	May 15, 1836 (Saros 135)	April 15, 1847 (Saros 136)
March 15, 1858 (Saros 137)	February 11, 1869 (Saros 138)	January 11, 1880 (Saros 139)	December 12, 1890 (Saros 140)	November 11, 1901 (Saros 141)
October 10, 1912 (Saros 142)	September 10, 1923 (Saros 143)	August 10, 1934 (Saros 144)	July 9, 1945 (Saros 145)	June 8, 1956 (Saros 146)
May 9, 1967 (Saros 147)	April 7, 1978 (Saros 148)	March 7, 1989 (Saros 149)	February 5, 2000 (Saros 150)	January 4, 2011 (Saros 151)
December 4, 2021 (Saros 152)	November 3, 2032 (Saros 153)	October 3, 2043 (Saros 154)	September 2, 2054 (Saros 155)	August 2, 2065 (Saros 156)
July 1, 2076 (Saros 157)	June 1, 2087 (Saros 158)

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
April 24, 1819 (Saros 145)	April 3, 1848 (Saros 146)	March 15, 1877 (Saros 147)
February 23, 1906 (Saros 148)	February 3, 1935 (Saros 149)	January 14, 1964 (Saros 150)
December 24, 1992 (Saros 151)	December 4, 2021 (Saros 152)	November 14, 2050 (Saros 153)
October 24, 2079 (Saros 154)	October 5, 2108 (Saros 155)	September 15, 2137 (Saros 156)
August 25, 2166 (Saros 157)	August 5, 2195 (Saros 158)