Talk:Transit of Mercury

File:Mercury transit 2.jpg to appear as POTD soon
Hello! This is a note to let the editors of this article know that File:Mercury transit 2.jpg will be appearing as picture of the day on November 7, 2011. You can view and edit the POTD blurb at Template:POTD/2011-11-07. If this article needs any attention or maintenance, it would be preferable if that could be done before its appearance on the Main Page so Wikipedia doesn't look bad. :) Thanks!  howcheng  {chat} 19:57, 4 November 2011 (UTC)

Error in Intervals?
Last transit Nov 2006. Next transit May 2016. That is 9.5 years. Therefore why does article state transits only occur every 7, 13 or 33 years - or are the dates wrong?

"November transits occur at intervals of 7, 13, or 33 years ; May transits only occur at intervals of 13 or 33 years. The last three transits occurred in 1999, 2003 and 2006 ; the next will occur in 2016." Tiddy (talk) 03:46, 7 November 2011 (UTC)
 * The intervals are from one November transit to the next November transit, or from one May transit to the next May transit. Since you're measuring the time between one November transit and the next May transit, the numbers won't come out right. I've reworded that sentence to make its intended meaning clearer. Double sharp (talk) 04:52, 7 June 2012 (UTC)

Apology
I entered an item twice then mistakenly deleted someone else's comment instead of my repeated entry. Now I cant find that deleted item to reinstate it, as there appears to be no history section for discussion items. Sorry. Tiddy (talk) 01:45, 16 November 2011 (UTC)

Wrong number display
I changed the years of simultaneous Mercury and Venus transits. The numbers were mangled. The text The last simultaneous transit occurred in 373173 BC showed 373,173 BC which was very confusing it could mean both the years 373 and 173 BC. The macro issues wrong results as it does not observe ISO standards which prescribe spaces rather than commas as thousands separator. More Wikipedia pages have this error. S k a t e b i k e r (talk) 11:36, 11 May 2012 (UTC)

Transits of Mercury in the (far) past and also in the (far) future.
Hallo everyone. Read also https://en.wikipedia.org/w/index.php?title=Transit_of_Mercury&oldid=726166700 Greetings of Nico from Gouda, the Netherlands. 84.80.54.162 (talk) 15:56, 5 July 2016 (UTC)

The nowadays May transits
After about the year +12,000 the backwards motion of the descending node of the orbit of Mercury as seen from the Earth will change in a forward motion and this means that then after each 217 year the chords of the transits of Mercury on the solar disc will move Southwards instead of Northwards (which it nowadays does).

For example 217 years series #2: Please note: only each tenth transit of this series is listed, thus after each 10 x 217 years = 2170 years. 1937/05/11 - 0.26544 (first transit of this 217 years series) 4107/06/05 - 0.20290 6277/06/29 - 0.15319  8447/07/24 - 0.11838 10617/08/18 - 0.09853 12787/09/13 - 0.09382 14957/10/08 - 0.10249 17127/11/03 - 0.12260 19297/11/27 - 0.15251 21467/12/25 - 0.18880 23638/01/19 - 0.22914 25591/02/12 - 0.26797 (last transit of this 217 years series, after 9 instead of 10 x 217 years)

The solar radius is about 0.2700 during each transit and always Mercury will pass South of the midpoint of the solar disc. From -50,000 till +50,000 there will be about +42,000 a second 'turningpoint' of the Marcury transits at the descending node and from then it will moves backwards again just as it nowadays does as seen from the Earth. Source: http://www.solexorb.it/SolexOld/ and then click on Mercury.

Please note: The pair of May transits 1937/05/11 - 1957/05/06 which ends in 2588/05/17 - 2608/05/13 (217 years series #20 will then end) returns in 14740/10/05 - 14760/10/01 (217 years series #20 will then restart).

The nowadays November transits
Before about the year -9000 the forward motion of the ascending node of the orbit of Mercury as seen from the Earth was changed in a backwards motion and this means that then after each 217 year the chords of the transits of Mercury on the solar disc moved Southwards instead of Northwards (which it nowadays does).

For example 217 years series #1: -22739/07/10 - 0.27003 (first transit of this 217 years series) After 4 x 217 years = 868 years -21871/07/14 - 0.25833 From now after each 10 x 217 years = 2170 years -19701/07/24 - 0.23217 -17531/08/03 - 0.20926 -15361/08/13 - 0.19001 -13191/08/23 - 0.17436 -11021/09/02 - 0.16312 -8851/09/12 - 0.15789  -6681/09/23 - 0.15941  -4511/10/02 - 0.17031  -2341/10/13 - 0.19115   -171/10/23 - 0.22304   1999/11/15 - 0.26750  (last transit of this 217 years series) Please note: before 1582 the Julian Calendar is used! The solar radius is about 0.2700 during each transit and always Mercury will pass North of the midpoint of the solar disc.

Because both nodes are turning forward and backwards in direction in time, a 217 years series can last about 50,000 years! For example the 217 years series of which the november transit of 1914/11/07 is a member of it, began on -35410/05/06 and will end on 14284/04/05. But from -50,000 till +50,000 there are NO more 'turningpoints' of the transits of Mercury at the ascending node as seen from the Earth. Source: http://www.solexorb.it/SolexOld/ and then click on Mercury. 84.80.54.162 (talk) 17:10, 1 August 2016 (UTC)

The 217-yearseries
Because the 217 year timeperiod is very more accuracy than the wellknown 46 years timeperiod, you can add an extra column on http://fourmilab.ch/documents/canon_transits/ and then click in the Transit Index Table on 40540, you get then this table below. But unfortunately in this table non-central transits such in 1937 and 2608 (2608 is the last one of the 217-yearsseries #20) are NOT listed! Please note: after the year -1 follows the year 1 in this long table! But on https://eclipse.gsfc.nasa.gov/transit/catalog/MercuryCatalog.html fortunately the transit of 1937 is listed. Date              Sunrad  Max. # of 217-yearsseries ...               ...     ...     ...        1776-11-02 21:35   0.2690  0.2626  39   1782-11-12 15:07   0.2696  0.2622   1   1786-05-04 05:31   0.2641  0.1919  18   1789-11-05 15:07   0.2692  0.1227  29   1799-05-07 12:43   0.2639  0.0939   8   1802-11-09 08:52   0.2693  0.0167  19   1815-11-12 02:24   0.2695  0.1543   9   1822-11-05 02:24   0.2690  0.2335  37   1832-05-05 12:14   0.2641  0.1352  16   1835-11-07 19:55   0.2692  0.0942  27   1845-05-08 19:26   0.2639  0.1516   6   1848-11-09 13:40   0.2693  0.0450  17   1861-11-12 07:11   0.2695  0.1825   7   1868-11-05 07:11   0.2690  0.2046  35   1878-05-06 18:57   0.2641  0.0804  14   1881-11-08 00:43   0.2692  0.0658  25   1891-05-10 02:09   0.2639  0.2089   4   1894-11-10 18:28   0.2693  0.0737  15   1907-11-14 12:00   0.2695  0.2105   5   1914-11-07 12:00   0.2691  0.1756  33   1924-05-08 01:40   0.2640  0.0250  12   1927-11-10 05:45   0.2692  0.0375  23   1937-05-11 08:59           955.5    2 (re-first transit of an OLD 217-yearsseries, because at the descending node the transits move backward instead of forward such as at the ascending node does after each 217 year) 1940-11-11 23:16  0.2694  0.1021  13   1953-11-14 16:48   0.2695  0.2391   3   1957-05-06 01:11   0.2642  0.2525  20   1960-11-07 16:48   0.2691  0.1469  31   1970-05-09 08:09   0.2640  0.0312  10   1973-11-10 10:19   0.2692  0.0138  21   1986-11-13 04:04   0.2694  0.1306  11   1993-11-06 03:50   0.2689  0.2577  39   1999-11-15 21:35   0.2695  0.2672   1 (last transit of this 217-yearsseries) 2003-05-07 07:40  0.2642  0.1973  18 (re-first total transit on -9932-03-08 and re-last total transit on 64718-05-30) 2006-11-08 21:35  0.2691  0.1177  29   2016-05-09 14:52   0.2640  0.0880   8 (re-first total transit on -2975-04-07 and re-last total transit on 30010-04-05) 2019-11-11 15:07  0.2692  0.0238  19 (first total transit on -31399-05-27 and last total transit on 9615-02-11) 2032-11-13 08:52  0.2694  0.1588   9   2039-11-07 08:38   0.2689  0.2287  37   2049-05-07 14:24   0.2642  0.1427  16   2052-11-09 02:24   0.2691  0.0888  27   2062-05-10 21:35   0.2640  0.1442   6   2065-11-11 19:55   0.2693  0.0510  17   2078-11-14 13:40   0.2694  0.1871   7   2085-11-07 13:26   0.2690  0.2000  35   2095-05-08 21:07   0.2642  0.0867  14   2098-11-10 07:11   0.2691  0.0599  25   2108-05-12 04:19   0.2640  0.2010   4   2111-11-14 00:43   0.2693  0.0793  15   2124-11-15 18:28   0.2694  0.2161   5   2131-11-09 18:14   0.2690  0.1712  33   2141-05-10 03:35   0.2641  0.0310  12   2144-11-11 12:00   0.2691  0.0316  23   2154-05-13 11:02   0.2640  0.2581   2   2157-11-14 05:31   0.2693  0.1078  13   2170-11-16 23:16   0.2694  0.2443   3   2174-05-08 03:21   0.2643  0.2572  20   2177-11-09 23:02   0.2690  0.1422  31   2187-05-11 10:19   0.2641  0.0267  10   2190-11-12 16:48   0.2691  0.0028  21   2203-11-16 10:33   0.2693  0.1359  11   2210-11-09 10:19   0.2688  0.2535  39   2220-05-09 09:50   0.2643  0.2030  18   ...                ...     ...     ...

The number of the nowadays November-transits in 217 years is nowadays slowly decreasing: -1 > 37: 8x 37 - -1 (-348 - 960) 1 > 39: 4x 39 - 1 (1342 - 1999) 3 > 41: 2x 41 - 3 (2815 - 3038) 5 > 43: 1x 43 - 5 (4071 and 4077) 7 > 45: 0x 45 - 7 (after 7e in 4899 follows in the first next 217 jaar-cyclus 45b in 5110) 9 > 47: 0x 47 - 9 (after 9e in 5939 - Jan. 1, follows (also) in the first next 217 jaar-cyclus 47b in 6149) and so on. (b = (re)begin of a new 217 year-series Mercury-transits, e = the (re)end of an old 217 year-series Mercury-transits)

The number of the nowadays May-transits in 217 years is nowadays slowly increasing:

Two transits in 20 years: not before the pairs 155 (the re-begin of the 217 years series #4) - 175 and 372 - 392 (the re-end of the 217 years series #22)(2x), and then followed by 1937 (the re-begin of the 217 years series #2) - 1957 till 2588 - 2608 (the re-end of the 217 years series #20)(4x), and then followed by 3936 (the re-begin of the 217 years series #0) - 3956 till 6106 - 6126 (the re-end of the 217 years series #18)(11x) and then followed from the pair 6152 (the re-begin of the 217 years series #-2) - 6172 till far after 12,000.

At the nowadays November transits at the ascending node of the orbit of Mercury: If a new 217 year series has began, the next 217 year series will begin after .x217 years - 46 years. At the nowadays  May  transits at the  descending node of the orbit of Mercury: If a new 217 year series has began, the next 217 year series will begin after .x217 years + 46 years.

84.80.54.162 (talk) 17:56, 1 November 2019 (UTC)
 * You should propose specific changes to the article that you think need to be made. Ruslik_ Zero 08:02, 3 November 2019 (UTC)

More citations needed
In response to the ITN nomination, I've gone through the article and added tags. I count 36 of them now, in virtually every section. Someone interested will have to fix it.  starship .paint  (talk) 14:49, 12 November 2019 (UTC)
 * - thank you for citing the table. There appears to be some inconsistencies. For 1605, the three values cited correspond to "II", "Greatest" and "III" columns. For 2032, the three values cited correspond to "I", "Greatest" and "IV" columns. Which should be used, II/III or I/IV?  starship .paint  (talk) 08:16, 13 November 2019 (UTC)
 * - as you are part of Wiki Solar System, can you advise me on the above issue? Thanks.  starship .paint  (talk) 08:56, 17 November 2019 (UTC)
 * Given that the columns are labeled Start and End I would say that the I/IV times are more appropriate, esp. given that the NASA source defines I as "transit begins" and IV as "transit ends". That's what the average person would expect.
 * Also, the label in the time column says UTC. The NASA site (and most modern ephemerides) use UT1, which they often simply call UT. UTC is an atomic time and UT1 is an Earth rotation time. --mikeu talk 08:13, 28 November 2019 (UTC)

wrong title

 * This page should be renamed as "Mercury transit" and not as "transit of Mercury". This is an event when Mercury transits Sol, not the other way around.  Nicole Sharp (talk) 21:29, 15 May 2022 (UTC)
 * I went ahead to move the page and fixed the double redirects. Nicole Sharp (talk) 21:33, 15 May 2022 (UTC)
 * In scientific papers the term "transit of Mercury" is used much more frequently than "Mercury transit", but they are both technically correct. Praemonitus (talk) 01:50, 16 May 2022 (UTC)
 * WP:COMMONNAME has the correct procedure which I believe would point to "Transit of Mercury". I mentioned the issue at WT:WikiProject Solar System. Johnuniq (talk) 03:14, 16 May 2022 (UTC)


 * A "Mercury transit of Sol" is when Mercury transits Sol. Whereas a "Solar transit of Mercury" is impossible.  When Sol (or Luna) passes in front of Mercury, it is a Solar (or Lunar) occultation of Mercury instead since Sol and Luna have a much larger angular size than Mercury does.  It is theoretically possible to observe a transit of Mercury, but a transit of Mercury can only occur when an object much smaller in angular size than Mercury (such as an asteroid or a satellite) passes in front of (transits) Mercury, making the likelihood of such an observation extremely rare (and difficult).  Nicole Sharp (talk) 17:13, 16 May 2022 (UTC)
 * The Oxford Dictionary of Astronomy: Second Edition Revised (2012) states "Transits of Mercury are more common than those of Venus. Forthcoming transits of Mercury are on&hellip;.  The next transit of Venus is on&hellip;."  However, this is in contrast to the primary definition of "transit, planetary ", which is: "The passage of one object in front of another of larger apparent diameter, such as Mercury or Venus in front of the Sun&hellip;.  Mercury and Venus transit the Sun&hellip;."  "Mercury transit of Sol" is unambiguous with regard to which object is in transit, whereas "transit of Mercury" is ambiguous and can refer to either Mercury transiting Sol or to another object such as an asteroid or satellite transiting Mercury.  Nicole Sharp (talk) 17:39, 16 May 2022 (UTC)
 * With regard to the definitions provided by the Oxford Dictionary of Astronomy, you can revert my edits if you wish since both "transit of Mercury" and "Mercury transit" are terms used to refer to when Mercury transits Sol, but if my edits are reverted, then a clarification should be provided in the article that a "transit of Mercury" could also refer to any smaller object passing in front of Mercury, instead of Mercury passing in front of Sol. I think leaving the article as "Mercury transit" (i.e. a Mercury transit of Sol and not a Solar transit of Mercury) is less ambiguous, which is my preference.  Nicole Sharp (talk) 17:39, 16 May 2022 (UTC)
 * The common usage is "transit of Mercury" with the subsequent "across the Sun" being both implicit and rather obvious. A transit of the Sun across Mercury is called an occultation. Praemonitus (talk) 17:58, 16 May 2022 (UTC)
 * The Transit of X articles, with Astronomical transit, show that the common meaning of "Transit of X" is that an object (Mars or Venus) passes between the Sun and the Earth. Unless otherwise specified, it is understood that a transit means an observer on Earth sees a black dot move across the Sun. I believe there are two editors favoring "Transit of Mercury" with one for "Mercury transit" so I will restore the original title if there is no further objection (or someone else might like to do it). As a contested move, WP:RSPM should be followed if necessary. Johnuniq (talk) 03:34, 17 May 2022 (UTC)
 * Transits that I have personally photographed include:
 * Mercury transit of Sol
 * ISS transit of Sol
 * ISS transit of Luna
 * Ganymede transit of Jupiter
 * The nomenclature "transit of X" to refer to an object X transiting object Y is ambiguous and inaccurate, even if commonly used. The only reason that such nomenclature can avoid ambiguity is when used for specific objects that overwhelmingly only transit a specific other object and overwhelmingly are not transited themselves by other objects.  For example, it is theoretically possible for Ganymede to transit Saturn instead of Jupiter, but such a phenomenon would be extremely rare.  Likewise, it is theoretically possible for an asteroid or non-Galilean Jovian moon to transit Ganymede (a syzygy with another Galilean moon would be an eclipse and not a transit due to their similar angular sizes) but again such a phenomenon would be extremely rare (and require a very large aperture to resolve, likely with a space telescope).  Saying "transit of Ganymede" or "transit of Mercury" is technically ambiguous but only when referring to all possible use-cases of the term (requiring disambiguation or clarification within the article if using an ambiguous title that could refer to other events).  Nicole Sharp (talk) 18:48, 18 May 2022 (UTC)
 * Astronomy has a fair amount of legacy terminology that isn't necessarily optimal usage or even logical. (E.g. late-type star and early-type star.) Presumably that's the case here, since transits have been reported for centuries. Wikipedia isn't here to correct that; just to report it. Hence, WP:COMMONNAME. Praemonitus (talk) 19:49, 18 May 2022 (UTC)
 * That's a good point. I once drove a chemist friend nuts by explaining astronomical Metallicity. He almost screamed when I told him that we consider oxygen to be a "metal." --mikeu talk 22:38, 19 May 2022 (UTC)
 * Transit of Mercury is the most commonly used title in academic, news, and educational sources that we rely on. While the phrase "Mercury transit" often appears in the literature it is rarely used as a title for the general subject. The recent name change was arbitrary and has consequences beyond what appears at the top of this articles. We would have to rename transit of Venus and extensively rewrite the text of articles mentioning the phenomena and also rename categories if this convention were adopted. --mikeu talk 14:32, 19 May 2022 (UTC)
 * Transit of Mercury (and Transit of Venus) is by far the most common title used in the astronomical literature as a full text search in the SAO/NASA Astrophysics Data System will show. There is absolutely no need to change the current title on Wikipedia. Please revert it. AstroLynx (talk) 07:35, 27 May 2022 (UTC)
 * I restored the title Transit of Mercury. Johnuniq (talk) 09:25, 27 May 2022 (UTC)