A transit is the passage of a planet across the Sun's bright disk. At this time, the planet can be seen as a small black disk slowly moving in front of the Sun. The orbits of Mercury and Venus lie inside Earth's orbit, so they are the only planets which can pass between Earth and Sun to produce a transit. Transits are very rare astronomical events. In the case of Venus, there are on average two transits every one and a quarter centuries. A transit of Venus occurs only if the planet is in inferior conjunction with the Sun (between Earth and Sun) and is also crossing the through Earth's orbital plane (the Ecliptic). During the present period in Earth's history, Venus's orbit crosses Earth's orbital plane in early June and early December each year. If the Venus is passing between the Earth and Sun at that time, a transit will be seen.
During the six millennium period 2000 BCE to 4000 CE1, Earth experiences 81 transits of Venus across the Sun. These events can be organized into two groups:
All Transits = 81 = 100.0%
June (Descending Node2) = 44 = 54.3 %
December (Ascending Node3) = 37 = 45.7 %
When a transit of Venus occurs, a second one often follows eight years later. This is because the orbital periods of Venus (224.701 days) and Earth (365.256 days) are in an 8 year (2922 days) resonance with each other. In other words, in the time it takes Earth to orbit the Sun eight times, Venus completes almost exactly thirteen revolutions about the Sun. As a result, Venus and Earth line up in the same positions with respect to the Sun. Actually, the two orbital periods are not quite commensurate with each other since Venus arrives at the eight year rendezvous about 2.45 days earlier that Earth. After the third eight-year cycle, Venus arrives too early for a transit to occur.
The next transit season occurs either 105.5 years or 121.5 years later at the opposite node of Venus' orbit. Once again, a pair of transits will often occur separated by eight years. This recurrence pattern of 8 + 105.5 + 8 + 121.5 years can be seen repeating itself in the catalog of Venus transits. An example of the pattern can be seen in the transits of 1631, 1639, 1761, 1769, 1874, 1882, 2004 and 2012. Occasionally, one of the eight year "double-transits" may disappear from the catalog for several centuries because one of them is a near miss. For instance, note the "missing" transits of 1388, 1145, 0902, 0659, 0416, etc..
A useful way to organize the transits is by grouping them into series where each member of a series is separated by 88,756 days or 243 years (= sum of 8 + 105.5 + 8 + 121.5 years). Thus, the transits of 1518, 1761 and 2004 would belong to one series, while the transits of 1639, 1882 and 2125 would belong to another series. Such transit series are quite long-lived and may last 5,000 years or more. For example, Series 4 (December at Ascending Node) began in -1763 (1764 BCE) and will run through 2854 (a grazing transit) for a total of 20 transits spanning 4617 years. These transit families are quite analogous to the Saros series for solar and lunar eclipses.
The position of the orbital nodes of Venus with respect to Earth are slowly changing with time. Five thousand years ago, transits occurred around May 21 and November 19. At present, the transits occur within a day of June 7 and December 9. In about 1500 years, the transits will occur during Earth's solstices (June 21 and December 22). This trend in the shift of transit dates is readily apparent in the catalog below. Over a period of approximately eighty thousand years, the transit dates will migrate forward one complete cycle through the seasons.
The following catalog contains predictions for every transit of Venus during the six thousand year interval 2000 BCE through 4000 CE. The information for each transit in the catalog is summarized as follows. The calendar date6 and geocentric Universal Time7 of the four transit contacts8 and the instant of greatest transit9 are found in the first six columns. The Sun's coordinates (Right Ascension and Declination) and the Greenwich Sidereal Time at 00:00 UT are given next. The minimum separation between the centers of Venus and the Sun is listed in arc-seconds. Finally the transit series10 is given.
The individual columns in each table are described in greater detail in the Key to Transit Catalogs.
Transit Contact Times (UT)
------------------------------------- Minimum Sun Sun Transit
Date I II Greatest III IV Sep. RA Dec GST Series
h:m h:m h:m h:m h:m " h ° h
-1998 Nov 18 07:34 07:51 11:20 14:50 15:07 374.0 14.541 -15.31 2.665 2
-1892 May 21 16:18 16:37 19:26 22:15 22:35 617.5 2.721 16.16 14.879 1
-1884 May 19 09:08 09:26 12:30 15:34 15:52 545.4 2.581 15.50 14.733 3
-1763 Nov 20 21:46 - 22:56 - 00:06 966.6 14.831 -16.65 2.961 4
-1755 Nov 18 08:43 09:01 12:18 15:36 15:53 474.8 14.669 -15.91 2.804 2
-1649 May 23 21:54 22:16 00:45 03:13 03:35 696.9 2.872 16.83 15.030 1
-1641 May 20 14:26 14:43 18:02 21:20 21:37 459.9 2.732 16.20 14.884 3
-1520 Nov 20 21:41 22:16 23:44 01:12 01:47 871.8 14.961 -17.21 3.099 4
-1512 Nov 18 09:32 09:51 12:51 15:50 16:10 585.4 14.797 -16.48 2.942 2
-1406 May 23 03:31 03:57 05:57 07:56 08:22 780.4 3.024 17.47 15.181 1
-1398 May 20 19:19 19:34 23:03 02:31 02:47 384.6 2.883 16.86 15.034 3
-1277 Nov 22 21:28 21:53 00:09 02:24 02:49 760.3 15.090 -17.74 3.237 4
-1269 Nov 19 10:28 10:49 13:27 16:05 16:26 684.5 14.928 -17.04 3.081 2
-1163 May 23 09:07 09:42 11:01 12:20 12:55 858.1 3.177 18.08 15.332 1
-1155 May 21 00:28 00:43 04:20 07:57 08:13 295.9 3.036 17.50 15.186 3
-1034 Nov 22 21:38 22:00 00:42 03:24 03:45 665.6 15.223 -18.25 3.376 4
-1026 Nov 19 11:15 11:42 13:45 15:49 16:15 796.4 15.058 -17.58 3.219 2
-0920 May 23 15:00 - 16:00 - 17:00 942.2 3.332 18.67 15.483 1
-0912 May 21 05:13 05:28 09:11 12:53 13:08 222.1 3.190 18.11 15.337 3
-0791 Nov 22 21:19 21:38 00:43 03:49 04:07 553.1 15.355 -18.74 3.514 4
-0783 Nov 19 12:07 12:48 13:58 15:08 15:49 899.2 15.190 -18.10 3.357 2
-0669 May 22 10:02 10:17 14:03 17:50 18:05 137.4 3.345 18.69 15.488 3
-0548 Nov 22 21:15 21:33 00:54 04:15 04:32 451.2 15.489 -19.21 3.652 4
-0540 Nov 19 - - 13:53 - - 1012.3 15.322 -18.59 3.494 2
-0426 May 22 14:38 14:52 18:41 22:30 22:45 61.5 3.502 19.25 15.638 3
-0305 Nov 23 20:39 20:56 00:30 04:04 04:20 335.5 15.623 -19.66 3.789 4
-0183 May 22 19:00 19:15 23:04 02:53 03:07 11.0 3.659 19.76 15.788 3
-0062 Nov 23 20:19 20:34 00:16 03:58 04:14 229.8 15.759 -20.08 3.927 4
Transit Contact Times (UT)
------------------------------------- Minimum Sun Sun Transit
Date I II Greatest III IV Sep. RA Dec GST Series
h:m h:m h:m h:m h:m " h ° h
0060 May 23 23:20 23:34 03:23 07:11 07:25 87.4 3.817 20.25 15.939 3
0181 Nov 22 19:36 19:52 23:39 03:27 03:42 114.3 15.895 -20.48 4.064 4
0303 May 24 03:27 03:42 07:28 11:13 11:28 157.7 3.977 20.71 16.089 3
0424 Nov 22 19:01 19:17 23:05 02:54 03:10 9.6 16.033 -20.86 4.201 4
0546 May 24 07:35 07:50 11:31 15:13 15:28 232.3 4.138 21.13 16.239 3
0554 May 22 03:42 - 04:51 - 06:00 933.6 3.990 20.72 16.093 5
0667 Nov 23 18:20 18:36 22:24 02:11 02:27 99.2 16.172 -21.21 4.338 4
0789 May 24 11:33 11:48 15:24 19:00 19:15 307.6 4.300 21.52 16.389 3
0797 May 22 06:41 07:18 08:32 09:45 10:23 866.6 4.151 21.14 16.243 5
0910 Nov 23 17:28 17:44 21:28 01:11 01:27 207.9 16.312 -21.53 4.475 4
1032 May 24 15:18 15:34 19:03 22:32 22:48 373.4 4.463 21.87 16.539 3
1040 May 22 10:02 10:29 12:23 14:18 14:45 791.8 4.314 21.52 16.393 5
1153 Nov 23 16:45 17:01 20:38 00:15 00:31 307.6 16.454 -21.83 4.613 4
1275 May 25 19:00 19:17 22:37 01:57 02:14 444.9 4.627 22.18 16.689 3
1283 May 23 13:04 13:27 15:44 18:01 18:25 733.6 4.477 21.87 16.542 5
1396 Nov 23 15:43 16:00 19:25 22:49 23:06 424.3 16.595 -22.10 4.750 4
1518 May 26 22:28 22:45 01:56 05:06 05:24 505.3 4.791 22.45 16.838 3
1526 May 23 16:13 16:34 19:11 21:48 22:08 666.7 4.640 22.18 16.692 5
1631 Dec 07 03:51 04:59 05:19 05:40 06:47 939.3 16.912 -22.64 5.045 6
1639 Dec 04 14:57 15:15 18:25 21:36 21:54 523.6 16.738 -22.34 4.888 4
1761 Jun 06 02:02 02:20 05:19 08:18 08:37 570.4 4.957 22.69 16.988 3
1769 Jun 03 19:15 19:34 22:25 01:16 01:35 609.3 4.805 22.44 16.842 5
1874 Dec 09 01:49 02:19 04:07 05:56 06:26 829.9 17.056 -22.82 5.182 6
1882 Dec 06 13:57 14:17 17:06 19:55 20:15 637.3 16.881 -22.56 5.025 4
Transit Contact Times (UT)
------------------------------------- Minimum Sun Sun Transit
Date I II Greatest III IV Sep. RA Dec GST Series
h:m h:m h:m h:m h:m " h ° h
2004 Jun 08 05:13 05:33 08:20 11:07 11:26 626.9 5.121 22.89 17.137 3
2012 Jun 06 22:09 22:27 01:29 04:32 04:49 554.4 4.969 22.68 16.991 5
2117 Dec 11 23:58 00:21 02:48 05:15 05:38 723.6 17.201 -22.97 5.320 6
2125 Dec 08 13:15 13:38 16:01 18:24 18:48 736.4 17.026 -22.74 5.163 4
2247 Jun 11 08:42 09:03 11:33 14:04 14:25 691.3 5.289 23.05 17.287 3
2255 Jun 09 01:08 01:25 04:38 07:51 08:08 491.9 5.135 22.87 17.141 5
2360 Dec 13 22:32 22:52 01:44 04:35 04:56 625.7 17.348 -23.09 5.458 6
2368 Dec 10 12:29 13:00 14:45 16:31 17:01 836.4 17.172 -22.90 5.301 4
2490 Jun 12 11:39 12:02 14:17 16:32 16:55 741.1 5.454 23.17 17.436 3
2498 Jun 10 03:48 04:05 07:25 10:45 11:02 442.7 5.301 23.02 17.290 5
2603 Dec 16 20:43 21:02 00:13 03:25 03:43 517.1 17.494 -23.18 5.596 6
2611 Dec 13 12:04 13:07 13:34 14:01 15:04 934.8 17.319 -23.03 5.440 4
2733 Jun 15 15:02 15:30 17:18 19:06 19:34 808.3 5.623 23.24 17.587 3
2741 Jun 13 06:33 06:49 10:17 13:44 14:00 385.6 5.468 23.14 17.440 5
2846 Dec 16 19:30 19:47 23:11 02:35 02:52 432.1 17.643 -23.24 5.735 6
2854 Dec 14 - - 12:19 - - 1026.7 17.466 -23.12 5.578 4
2976 Jun 16 17:45 18:19 19:44 21:10 21:44 850.5 5.791 23.28 17.735 3
2984 Jun 14 09:01 09:16 12:49 16:22 16:37 336.3 5.634 23.21 17.589 5
3089 Dec 18 17:39 17:55 21:31 01:06 01:23 320.6 17.790 -23.27 5.873 6
3219 Jun 19 20:50 21:46 22:19 22:52 23:49 908.1 5.957 23.28 17.885 3
3227 Jun 17 11:21 11:37 15:13 18:50 19:05 293.4 5.801 23.25 17.738 5
3332 Dec 20 16:16 16:32 20:14 23:56 00:12 235.5 17.939 -23.26 6.012 6
3462 Jun 22 23:29 - 00:27 - 01:26 948.1 6.123 23.24 18.034 3
3470 Jun 19 13:31 13:46 17:26 21:07 21:22 247.9 5.967 23.25 17.887 5
3575 Dec 23 14:29 14:44 18:32 22:19 22:34 131.5 18.087 -23.23 6.150 6
3705 Jun 24 - - 02:32 - - 989.3 6.289 23.16 18.182 3
3713 Jun 21 15:25 15:40 19:22 23:05 23:20 215.2 6.133 23.21 18.036 5
3818 Dec 25 12:57 13:12 17:01 20:50 21:05 41.1 18.237 -23.16 6.290 6
3956 Jun 23 17:22 17:37 21:21 01:06 01:21 175.2 6.300 23.13 18.184 5
The Julian calendar is used for all dates up to 1582 Oct 04. After that date, the Gregorian calendar is used. Due to the Gregorian Calendar reform, the day after 1582 Oct 04 (Julian calendar) is 1582 Oct 15 (Gregorian calendar). Note that Great Britain did not adopt the Gregorian calendar until 1752. For more information, see Julian and Gregorian Calendars.
To determine whether a transit is visible from a specific geographic location, it is simply a matter of calculating the Sun's altitude and azimuth during each phase of the transit. The calculations can be performed on any pocket calculator having trig functions (SIN, COS, TAN). Armed with the latitude and longitude of the location, the transit catalog provides all the additional information needed to make the calculations. For the equations and an example of how to calculate the Sun's altitude for a specific location, see Transit Visibility.
As an aid to historical research, two Excel 97 spreadsheet files have been prepared which perform the above calculations automatically. You simply enter the location name, latitude and longitude. Each of the tables then calculates the altitude of the Sun at that location for every contact for several dozen of transits. The two tables cover different time periods:
Please note that these files will not open properly unless you have Excel 97 (or newer) installed on your computer. When each of the spreadsheets is downloaded, it will be opened automatically in Excel where you will be able to enter the coordinates of any geographic location to calculate the transit circumstances. The spreadsheets are protected so that you can not accidently delete or edit any information required by the calculations. Only the name and coordinates of the geographic location (in the green box of each spreadsheet) may be modified.
The transit times in these tables are based of geocentric calculations. Because of parallax, the observed transit times for any given location may differ by up to 10 minutes. Furthermore, the Sun's actual altitude at a location may differ by up to 1 degree from the tables. Such precision is adequate for many applications especially since the geocentric approximation greatly simplifies the circumstances calculations.
All transit calculations are by Fred Espenak, and he assumes full responsibility for their accuracy. Besselian elements for the transit predictions are from "Transits" by Jean Meeus (Willmann-Bell, 1989). This is an indispensable reference for anyone wishing to do transit calculations.
Special thanks to eclipse chaser Michael Gill for enthusiastically and rigorously beta-testing this page and for catching typographic errors. (2003 March)
Permission is freely granted to reproduce this data when accompanied by an acknowledgment:
"Transit Predictions by Fred Espenak, NASA/GSFC"
