Solar eclipse of March 21, 2099

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.[1]

Solar eclipses 2098–2100
121	April 1, 2098 Partial	126	September 25, 2098 Partial
131	March 21, 2099 Annular	136	September 14, 2099 Total
141	March 10, 2100 Annular	146	September 4, 2100 Total

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.

Inex series members between 1901 and 2100:
July 20, 1925 (Saros 125)	June 30, 1954 (Saros 126)	June 11, 1983 (Saros 127)
May 20, 2012 (Saros 128)	April 30, 2041 (Saros 129)	April 11, 2070 (Saros 130)
March 21, 2099 (Saros 131)

It is a part of Saros cycle 131, repeating every 18 years, 11 days, containing 70 events. The series started with partial solar eclipse on August 1, 1125. It contains total eclipses from March 27, 1522 through May 30, 1612 and hybrid eclipses from June 10, 1630 through July 24, 1702, and annular eclipses from August 4, 1720 through June 18, 2243. The series ends at member 70 as a partial eclipse on September 2, 2369. The longest duration of totality was only 58 seconds on May 30, 1612. All eclipses in this series occurs at the Moon’s ascending node.

Series members 33–70 occur between 1702 and 2369
33	34	35
July 24, 1702	August 4, 1720	August 15, 1738
36	37	38
August 25, 1756	September 6, 1774	September 16, 1792
39	40	41
September 28, 1810	October 9, 1828	October 20, 1846
42	43	44
October 30, 1864	November 10, 1882	November 22, 1900
45	46	47
December 3, 1918	December 13, 1936	December 25, 1954
48	49	50
January 4, 1973	January 15, 1991	January 26, 2009
51	52	53
February 6, 2027	February 16, 2045	February 28, 2063
54	55	56
March 10, 2081	March 21, 2099	April 2, 2117
57	58	59
April 13, 2135	April 23, 2153	May 5, 2171
60	61	62
May 15, 2189	May 27, 2207	June 6, 2225
63	64	65
June 18, 2243	June 28, 2261	July 9, 2279
66	67	68
July 20, 2297	August 1, 2315	August 11, 2333
69	70
August 22, 2351	September 2, 2369