Eclipse Statistics

It's all very well digging into the theory -- what does this mean in practice? In particular, how often will I see an eclipse?

This page gives you some statistics about how often eclipses occur.

So how often can we see an eclipse? Well, as explained in Eclipse Cycles, there are two eclipse seasons per year (actually, one every 173 days) when an eclipse can occur. An eclipse season lasts for 37 days; since the Moon only takes 29 days to complete an orbit, we're guaranteed one solar and one lunar eclipse (which may or may not be total) every eclipse season. With an eclipse season happening a little more often than every 6 months, there are at least two -- and sometimes three -- in a year; so there should be at least 4 eclipses a year.

In fact, since one orbit of the Moon takes less time than the length of an eclipse season, it's quite possible to get two solar or two lunar eclipses in an eclipse season (but not two of each); this happens a bit more than every 4 years, on average, for solar eclipses, and about every 3 years for lunar eclipses. However, since the two eclipses have to be at either end of the season, the two eclipses are usually both small partial eclipses; but about every 300 years, a total solar eclipse and a partial solar eclipse occur in the same eclipse season. The last time this happened was in 1928; a tiny total eclipse in the far south, in May, was followed in June by a small partial eclipse in the far north. The next time this happens will be in July and August 2195.

So, every year sees at least 4 eclipses (2 solar and 2 lunar), somewhere on the Earth. About once in 3.5 years, 5 eclipses occur; 6 in a year happens ever 4.5 years or so; and you can get 7 eclipses in a year, but that's rare -- only about every 31 years. (The last year this happened was 1982; the next time will be 2038.)

Total eclipses are, of course, rarer. On average, a total solar eclipse happens about twice in three years, and total lunar eclipses are a little more frequent than that. It's possible to get 2 total solar eclipses in a year, but again this is rare; only every 170 years or so. However, two total lunar eclipses occur in a single year about once every 3.5 years, and 3 in a year about every 200 years.

Actually seeing an eclipse is a little more tricky, of course; you actually have to be in the right place at the right time. For solar eclipses, because the partial phase of a total solar eclipse covers a relatively large area, this can be seen about every 2 years, on average, from any given spot on the Earth. The much narrower track of the total eclipse falls over a particular place far less often -- the best guess is about every 360 years on the average, although they're distributed so randomly (in effect, though, of course, it's not really random) that a given spot might not see a total eclipse for centuries, or might see two within a few years. Some examples of the latter are shown in the USA Eclipse Bonanza page.

Lunar eclipses are much easier to see; because the action is happening on the Moon, and on the side facing us, anywhere that the Moon is up during the eclipse will see it (clouds permitting), whether it's partial or total.

Database Statistics

The following statistics are extracted from the searchable eclipse database:

All Eclipses

The database contains 24085 eclipses over 5000 years, from -1999 (2000 BC) to 3000 AD. There are between 4 and 7 eclipses in any calendar year; with an average of 4.82 eclipses per year.

There are:

2352 years with 4 eclipses (47.0%, 1 in 2.13 years)

1370 years with 5 eclipses (27.4%, 1 in 3.65 years)

1119 years with 6 eclipses (22.4%, 1 in 4.47 years)

159 years with 7 eclipses (3.2%, 1 in 31.45 years)

7 eclipses occur in 1908, 1917, 1935, 1973, 1982, 2038, 2094, among others.

The database contains 10536 complete eclipse seasons.

There are:

7526 eclipse seasons with 2 eclipses (71.4%, 1 in 1.40 seasons)

3010 eclipse seasons with 3 eclipses (28.6%, 1 in 3.50 seasons)

This table shows the number of eclipse seasons which contained each combination of eclipse types:

Number	First Eclipse	Second Eclipse	Third Eclipse
145 seasons	penumbral lunar	annular solar		1 in 72.66
51 seasons	penumbral lunar	hybrid solar		1 in 206.59
430 seasons	penumbral lunar	total solar		1 in 24.50
1118 seasons	partial lunar	annular solar		1 in 9.42
167 seasons	partial lunar	hybrid solar		1 in 63.09
12 seasons	partial lunar	partial solar		1 in 878.00
779 seasons	partial lunar	total solar		1 in 13.53
184 seasons	total lunar	annular solar		1 in 57.26
12 seasons	total lunar	hybrid solar		1 in 878.00
728 seasons	total lunar	partial solar		1 in 14.47
132 seasons	total lunar	total solar		1 in 79.82
142 seasons	annular solar	penumbral lunar		1 in 74.20
1132 seasons	annular solar	partial lunar		1 in 9.31
188 seasons	annular solar	total lunar		1 in 56.04
73 seasons	hybrid solar	penumbral lunar		1 in 144.33
127 seasons	hybrid solar	partial lunar		1 in 82.96
5 seasons	hybrid solar	total lunar		1 in 2107.20
753 seasons	partial solar	total lunar		1 in 13.99
408 seasons	total solar	penumbral lunar		1 in 25.82
800 seasons	total solar	partial lunar		1 in 13.17
140 seasons	total solar	total lunar		1 in 75.26
979 seasons	penumbral lunar	annular solar	penumbral lunar	1 in 10.76
36 seasons	penumbral lunar	annular solar	partial lunar	1 in 292.67
132 seasons	penumbral lunar	hybrid solar	penumbral lunar	1 in 79.82
467 seasons	penumbral lunar	total solar	penumbral lunar	1 in 22.56
36 seasons	partial lunar	annular solar	penumbral lunar	1 in 292.67
1344 seasons	partial solar	total lunar	partial solar	1 in 7.84
7 seasons	partial solar	total lunar	total solar	1 in 1505.14
9 seasons	total solar	total lunar	partial solar	1 in 1170.67

Solar Eclipses

11897 solar eclipses altogether (2.38 per year)

3172 total solar eclipses (26.7%, 1 every 1.58 years)

568 hybrid eclipses (4.8%, 1 every 8.80 years)

3960 annular eclipses (33.3%, 1 every 1.26 years)

4197 partial eclipses (35.3%, 1 every 1.19 years)

There are:

3625 years with 2 solar eclipses (72.5%, 1 in 1.38 years)

878 years with 3 solar eclipses (17.6%, 1 in 5.69 years)

472 years with 4 solar eclipses (9.4%, 1 in 10.59 years)

25 years with 5 solar eclipses (0.5%, 1 in 200.00 years)

Since year 1000, 5 solar eclipses occur in 1255, 1805, 1935, 2206, 2709, 2774, 2839, 2904.

There is a maximum of 2 total solar eclipses in any calendar year. There are:

1857 years with 0 total solar eclipses (37.1%, 1 in 2.69 years)

3114 years with 1 total solar eclipses (62.3%, 1 in 1.61 years)

29 years with 2 total solar eclipses (0.6%, 1 in 172.41 years)

Since year 1000, 2 total solar eclipses occur in 1014, 1209, 1358, 1535, 1554, 1712, 1889, 2057, 2252, 2429, 2606, 2801, 2996.

There are 1360 double solar eclipse seasons (1 in 3.68 years); of which 16 involve a total eclipse (1 in 312.50 years):

    -1859/05/24 19:43 S,T  and  -1859/06/23 02:56 S,P
    -1718/04/26 18:10 S,T  and  -1718/05/26 01:10 S,P
    -1451/06/12 21:06 S,P  and  -1451/07/12 04:02 S,T
    -1310/05/15 19:25 S,P  and  -1310/06/14 01:57 S,T
    -1169/04/17 17:40 S,P  and  -1169/05/17 00:17 S,T
     -716/06/16 16:43 S,T  and   -716/07/15 23:37 S,P
     -575/05/19 14:54 S,T  and   -575/06/17 21:29 S,P
     -434/04/21 12:56 S,T  and   -434/05/20 19:40 S,P
      -26/05/10 12:59 S,P  and    -26/06/08 20:12 S,T
      654/04/22 16:02 S,P  and    654/05/21 22:52 S,T
     1107/06/22 14:28 S,T  and   1107/07/21 21:19 S,P
     1248/05/24 12:14 S,T  and   1248/06/22 18:59 S,P
     1928/05/19 13:24 S,T  and   1928/06/17 20:27 S,P
     2195/07/07 15:35 S,P  and   2195/08/05 22:14 S,T
     2459/05/03 02:15 S,P  and   2459/06/01 09:39 S,T
     2912/07/06 00:19 S,T  and   2912/08/04 07:04 S,P

The database contains solar eclipses from saros series -13 to 190. There are 204 complete saros series (and 83 partial series). The number of eclipses in a series ranges from 70 (Saros 104, 116, 122, 123, 137, 138, 141, 144) to 86 (Saros 34, 52).

Lunar Eclipses

12188 lunar eclipses altogether (2.44 per year)

3502 total lunar eclipses (28.7%, 1 every 1.43 years)

4207 partial eclipses (34.5%, 1 every 1.19 years)

4479 penumbral eclipses (36.7%, 1 every 1.12 years)

Of the 4479 penumbral eclipses, 191 are total penumbral eclipses (ie. penumbral magnitude >= 1.000); this is 4.3% of the penumbral eclipses, or 1.6% of all lunar eclipses; 1 every 26.18 years.

There are:

3489 years with 2 lunar eclipses (69.8%, 1 in 1.43 years)

871 years with 3 lunar eclipses (17.4%, 1 in 5.74 years)

603 years with 4 lunar eclipses (12.1%, 1 in 8.29 years)

37 years with 5 lunar eclipses (0.7%, 1 in 135.14 years)

Since year 1000, 5 lunar eclipses occur in 1181, 1246, 1311, 1676, 1694, 1749, 1879, 2132, 2262, 2400, 2653, 2718, 2783, 2848, 2968.

There is a maximum of 3 total lunar eclipses in any calendar year. There are:

2956 years with 0 total lunar eclipses (59.1%, 1 in 1.69 years)

610 years with 1 total lunar eclipses (12.2%, 1 in 8.20 years)

1410 years with 2 total lunar eclipses (28.2%, 1 in 3.55 years)

24 years with 3 total lunar eclipses (0.5%, 1 in 208.33 years)

Since year 1000, 3 total lunar eclipses occur in 1414, 1479, 1544, 1917, 1982, 2485, 2550, 2615.

There are 1651 double lunar eclipse seasons (1 in 3.03 years); of which none involve a total eclipse.

The database contains lunar eclipses from saros series -20 to 183. There are 204 complete saros series (and 87 partial series). The number of eclipses in a series ranges from 71 (Saros 111, 113, 114, 128, 129, 132, 133, 135) to 87 (Saros 26, 43, 45).