The periodicity and recurrence of lunar (and solar) eclipses is governed by the Saros cycle, a period of approximately 6,585.3 days (18 years 11 days 8 hours). When two eclipses are separated by a period of one Saros, they share a very similar geometry. The two eclipses occur at the same node[1] with the Moon at nearly the same distance from Earth and at the same time of year. Thus, the Saros is useful for organizing eclipses into families or series. Each series typically lasts 12 to 15 centuries and contains 70 or more lunar eclipses.
Lunar eclipses of Saros 173 all occur at the Moon’s descending node and the Moon moves northward with each eclipse. The series will begin with a penumbral eclipse near the southern edge of the penumbra on 2787 Apr 24. The series will end with a penumbral eclipse near the northern edge of the penumbra on 4067 Jun 11. The total duration of Saros series 173 is 1280.14 years. In summary:
First Eclipse = 2787 Apr 24 13:54:20 TD
Last Eclipse = 4067 Jun 11 01:40:30 TD
Duration of Saros 173 = 1280.14 Years
Saros 173 is composed of 72 lunar eclipses as follows:
| Lunar Eclipses of Saros 173 | |||
| Eclipse Type | Symbol | Number | Percent |
| All Eclipses | - | 72 | 100.0% |
| Penumbral | N | 29 | 40.3% |
| Partial | P | 16 | 22.2% |
| Total | T | 27 | 37.5% |
The 72 lunar eclipses in Saros 173 occur in the order of 8N 7P 27T 9P 21N which corresponds to:
8 Penumbral
7 Partial
27 Total
9 Partial
21 Penumbral
The longest and shortest eclipses of Saros 173 are as follows.
Longest Total Lunar Eclipse: 3400 May 01 Duration = 01h39m39s
Shortest Total Lunar Eclipse: 3057 Oct 04 Duration = 00h29m33s
Longest Partial Lunar Eclipse: 3039 Sep 24 Duration = 03h14m16s
Shortest Partial Lunar Eclipse: 3688 Oct 22 Duration = 00h53m51s
Longest Penumbral Lunar Eclipse: 2913 Jul 09 Duration = 04h27m21s
Shortest Penumbral Lunar Eclipse: 4067 Jun 11 Duration = 00h22m48s
The largest and smallest magnitude partial eclipses of Saros 173 are:
Largest Partial Lunar Eclipse: 3544 Jul 28 Magnitude = 0.9944
Smallest Partial Lunar Eclipse: 3688 Oct 22 Magnitude = 0.0622
Local circumstances at greatest eclipse[2] for every lunar eclipse of Saros 173 are presented in the following catalog. For eclipses occurring between the years -1999 to +3000 (2000 BCE to 3000 CE), the sequence number in the first column links to a eclipse geometry diagram and a map from Five Millennium Canon of Lunar Eclipses: -1999 to +3000. A detailed key and additional information about the catalog can be found at: Key to Catalog of Lunar Eclipse Saros Series.
TD of Phase
Seq. Rel. Calendar Greatest Luna Ecl. Pen. Um. ---- Durations ----
Num. Num. Date Eclipse ΔT Num Type QSE Gamma Mag. Mag. Pen. Par. Total
s m m m
01 -34 2787 Apr 24 13:54:20 2965 9737 N t- -1.5381 0.0689 -0.9971 79.8 - -
02 -33 2805 May 04 21:08:11 3078 9960 N t- -1.4821 0.1689 -0.8915 123.4 - -
03 -32 2823 May 16 04:14:42 3192 10183 N t- -1.4192 0.2815 -0.7734 157.0 - -
04 -31 2841 May 26 11:15:35 3308 10406 N t- -1.3507 0.4045 -0.6451 185.4 - -
05 -30 2859 Jun 06 18:11:15 3427 10629 N t- -1.2771 0.5370 -0.5075 210.1 - -
06 -29 2877 Jun 17 01:03:49 3547 10852 N t- -1.1999 0.6762 -0.3635 231.7 - -
07 -28 2895 Jun 28 07:53:55 3670 11075 N t- -1.1194 0.8218 -0.2135 250.7 - -
08 -27 2913 Jul 09 14:42:35 3795 11298 N t- -1.0366 0.9716 -0.0597 267.4 - -
09 -26 2931 Jul 20 21:32:13 3921 11521 P t- -0.9536 1.1222 0.0944 281.6 72.0 -
10 -25 2949 Jul 31 04:23:42 4050 11744 P t- -0.8712 1.2719 0.2471 293.7 113.7 -
11 -24 2967 Aug 11 11:18:05 4181 11967 P h- -0.7900 1.4195 0.3973 304.0 140.5 -
12 -23 2985 Aug 21 18:16:56 4314 12190 P h- -0.7114 1.5628 0.5427 312.4 160.0 -
13 -22 3003 Sep 03 01:21:39 4449 12413 P h- -0.6364 1.6995 0.6811 319.2 174.7 -
14 -21 3021 Sep 13 08:33:59 4586 12636 P a- -0.5669 1.8263 0.8092 324.5 185.8 -
15 -20 3039 Sep 24 15:52:39 4726 12859 P a- -0.5016 1.9457 0.9295 328.6 194.3 -
16 -19 3057 Oct 04 23:21:22 4867 13082 T a- -0.4437 2.0517 1.0360 331.5 200.5 29.5
17 -18 3075 Oct 16 06:58:07 5010 13305 T a- -0.3914 2.1474 1.1322 333.6 205.1 54.8
18 -17 3093 Oct 26 14:45:49 5156 13528 T a- -0.3473 2.2283 1.2133 334.9 208.3 67.5
19 -16 3111 Nov 07 22:41:00 5303 13751 T p- -0.3086 2.2992 1.2844 335.7 210.6 75.9
20 -15 3129 Nov 18 06:46:58 5453 13974 T p- -0.2780 2.3552 1.3407 335.9 212.0 81.1
21 -14 3147 Nov 29 15:00:07 5604 14197 T- p- -0.2526 2.4016 1.3874 335.8 212.9 84.8
22 -13 3165 Dec 09 23:21:45 5758 14420 T- p- -0.2335 2.4364 1.4228 335.4 213.3 87.1
23 -12 3183 Dec 21 07:49:15 5914 14643 T- p- -0.2186 2.4632 1.4505 334.9 213.5 88.7
24 -11 3201 Dec 31 16:23:14 6072 14866 T- p- -0.2083 2.4814 1.4701 334.2 213.4 89.7
25 -10 3220 Jan 12 01:00:30 6232 15089 T- p- -0.2005 2.4950 1.4854 333.3 213.3 90.4
26 -09 3238 Jan 22 09:40:19 6394 15312 T- p- -0.1940 2.5057 1.4984 332.4 213.1 90.9
27 -08 3256 Feb 02 18:20:53 6558 15535 T- p- -0.1876 2.5160 1.5114 331.5 212.9 91.5
28 -07 3274 Feb 13 03:01:37 6724 15758 T- p- -0.1806 2.5273 1.5259 330.5 212.8 92.1
29 -06 3292 Feb 24 11:39:09 6892 15981 T- p- -0.1705 2.5440 1.5463 329.6 212.8 92.9
30 -05 3310 Mar 07 20:13:54 7062 16204 T- p- -0.1576 2.5656 1.5720 328.7 212.8 93.9
31 -04 3328 Mar 18 04:43:27 7235 16427 T- p- -0.1397 2.5962 1.6070 327.9 213.1 95.2
32 -03 3346 Mar 29 13:08:49 7409 16650 T- p- -0.1177 2.6341 1.6496 327.1 213.3 96.5
33 -02 3364 Apr 08 21:26:05 7586 16873 T- p- -0.0884 2.6854 1.7058 326.4 213.6 97.9
34 -01 3382 Apr 20 05:38:24 7764 17096 T- pp -0.0545 2.7452 1.7705 325.5 213.9 99.0
35 00 3400 May 01 13:42:40 7945 17319 T- pp -0.0135 2.8181 1.8481 324.6 213.9 99.6
36 01 3418 May 12 21:41:20 8128 17542 T+ pp 0.0327 2.7804 1.8151 323.5 213.5 99.5
37 02 3436 May 23 05:32:10 8312 17765 T+ pp 0.0860 2.6804 1.7195 322.0 212.6 98.1
38 03 3454 Jun 03 13:18:34 8499 17988 T+ pp 0.1433 2.5732 1.6164 320.2 211.0 95.2
39 04 3472 Jun 13 20:59:08 8688 18211 T+ -p 0.2057 2.4568 1.5036 317.9 208.6 90.1
40 05 3490 Jun 25 04:35:13 8879 18434 T+ -p 0.2723 2.3330 1.3831 314.9 205.0 82.2
TD of Phase
Seq. Rel. Calendar Greatest Luna Ecl. Pen. Um. ---- Durations ----
Num. Num. Date Eclipse ΔT Num Type QSE Gamma Mag. Mag. Pen. Par. Total
s m m m
41 06 3508 Jul 06 12:07:53 9072 18657 T -p 0.3419 2.2040 1.2567 311.3 200.3 70.2
42 07 3526 Jul 17 19:38:35 9267 18880 T -a 0.4133 2.0720 1.1267 307.0 194.3 51.4
43 08 3544 Jul 28 03:08:24 9465 19103 P -a 0.4858 1.9383 0.9944 302.0 186.9 -
44 09 3562 Aug 08 10:37:34 9664 19326 P -a 0.5588 1.8038 0.8608 296.2 177.9 -
45 10 3580 Aug 18 18:09:00 9865 19549 P -a 0.6302 1.6728 0.7300 289.8 167.3 -
46 11 3598 Aug 30 01:42:30 10069 19772 P -a 0.6997 1.5454 0.6021 282.8 155.0 -
47 12 3616 Sep 09 09:19:33 10274 19995 P -a 0.7666 1.4232 0.4790 275.4 140.8 -
48 13 3634 Sep 20 17:00:27 10482 20218 P -a 0.8303 1.3070 0.3613 267.5 124.4 -
49 14 3652 Oct 01 00:47:35 10691 20441 P -a 0.8890 1.2003 0.2525 259.6 105.7 -
50 15 3670 Oct 12 08:40:34 10903 20664 P -a 0.9426 1.1031 0.1530 251.7 83.4 -
51 16 3688 Oct 22 16:39:40 11117 20887 P -a 0.9914 1.0151 0.0622 243.9 53.8 -
52 17 3706 Nov 04 00:46:12 11333 21110 N -a 1.0339 0.9386 -0.0173 236.7 - -
53 18 3724 Nov 14 09:00:08 11551 21333 N -a 1.0706 0.8728 -0.0863 230.1 - -
54 19 3742 Nov 25 17:21:07 11771 21556 N -a 1.1013 0.8181 -0.1442 224.3 - -
55 20 3760 Dec 06 01:48:17 11993 21779 N -a 1.1270 0.7726 -0.1929 219.3 - -
56 21 3778 Dec 17 10:21:57 12217 22002 N -a 1.1474 0.7368 -0.2318 215.2 - -
57 22 3796 Dec 27 19:01:16 12443 22225 N -a 1.1633 0.7090 -0.2624 212.1 - -
58 23 3815 Jan 09 03:44:10 12672 22448 N -a 1.1763 0.6863 -0.2875 209.5 - -
59 24 3833 Jan 19 12:31:12 12902 22671 N -a 1.1861 0.6695 -0.3066 207.6 - -
60 25 3851 Jan 30 21:19:23 13134 22894 N -a 1.1951 0.6538 -0.3240 205.8 - -
61 26 3869 Feb 10 06:09:02 13369 23117 N -a 1.2028 0.6404 -0.3387 204.3 - -
62 27 3887 Feb 21 14:55:49 13606 23340 N -a 1.2130 0.6222 -0.3579 202.1 - -
63 28 3905 Mar 04 23:41:52 13844 23563 N -a 1.2236 0.6029 -0.3778 199.6 - -
64 29 3923 Mar 16 08:22:42 14085 23786 N -a 1.2388 0.5752 -0.4056 195.9 - -
65 30 3941 Mar 26 16:59:12 14328 24009 N -a 1.2571 0.5415 -0.4393 191.0 - -
66 31 3959 Apr 07 01:28:01 14573 24232 N -a 1.2814 0.4968 -0.4837 184.1 - -
67 32 3977 Apr 17 09:51:01 14820 24455 N -a 1.3102 0.4437 -0.5363 175.2 - -
68 33 3995 Apr 28 18:05:22 15069 24678 N -a 1.3457 0.3784 -0.6011 163.2 - -
69 34 4013 May 09 02:11:34 15320 24901 N -a 1.3872 0.3019 -0.6772 147.1 - -
70 35 4031 May 20 10:09:05 15573 25124 N -a 1.4353 0.2137 -0.7652 125.1 - -
71 36 4049 May 30 17:59:06 15828 25347 N -a 1.4885 0.1159 -0.8629 93.2 - -
72 37 4067 Jun 11 01:40:30 16085 25570 Ne -a 1.5481 0.0068 -0.9724 22.8 - -
[1] The Moon's orbit is inclined about 5 degrees to Earth's orbit around the Sun. The points where the lunar orbit intersects the plane of Earth's orbit are known as the nodes. The Moon moves from south to north of Earth's orbit at the ascending node, and from north to south at the descending node.
[2]Greatest eclipse is defined as the instant when Moon passes closest to the axis of Earth's shadow.
The Gregorian calendar is used for all dates from 1582 Oct 15 onwards. Before that date, the Julian calendar is used. For more information on this topic, see Calendar Dates. The Julian calendar does not include the year 0. Thus the year 1 BCE is followed by the year 1 CE (See: BCE/CE Dating Conventions ). This is awkward for arithmetic calculations. Years in this catalog are numbered astronomically and include the year 0. Historians should note there is a difference of one year between astronomical dates and BCE dates. Thus, the astronomical year 0 corresponds to 1 BCE, and astronomical year -1 corresponds to 2 BCE, etc..
The coordinates of the Sun used in these predictions are based on the VSOP87 theory [Bretagnon and Francou, 1988]. The Moon's coordinates are based on the ELP-2000/82 theory [Chapront-Touze and Chapront, 1983]. For more information, see: Solar and Lunar Ephemerides. The revised value used for the Moon's secular acceleration is n-dot = -25.858 arc-sec/cy*cy, as deduced from the Apollo lunar laser ranging experiment (Chapront, Chapront-Touze, and Francou, 2002).
The largest uncertainty in the eclipse predictions is caused by fluctuations in Earth's rotation due primarily to tidal friction of the Moon. The resultant drift in apparent clock time is expressed as ΔT and is determined as follows:
A series of polynomial expressions have been derived to simplify the evaluation of ΔT for any time from -1999 to +3000. The uncertainty in ΔT over this period can be estimated from scatter in the measurements.
The Besselian elements used in the predictions were kindly provided by Jean Meeus. All eclipse calculations are by Fred Espenak, and he assumes full responsibility for their accuracy. Some of the information presented on this web site is based on data originally published in Five Millennium Canon of Lunar Eclipses: -1999 to +3000 and Five Millennium Catalog of Lunar Eclipses: -1999 to +3000.
Permission is freely granted to reproduce this data when accompanied by an acknowledgment:
"Eclipse Predictions by Fred Espenak and Jean Meeus (NASA's GSFC)"
