<p>According to the Wikipedia article for <a href="https://en.wikipedia.org/wiki/Transit_of_Venus#Grazing_and_simultaneous_transits" rel="noreferrer">Transit of Venus</a>, the last time a transit of Mercury and a transit of Venus occurred at the same time was 22 September of 373,173 BC. This is a Featured Article and the statement has been on the page since December 2008, implying authenticity. But I cannot find an academic citation anywhere to back this up.</p>
<p>I <em>can</em> find an <a href="http://adsabs.harvard.edu/full/2004JBAA..114..132M" rel="noreferrer">academic citation</a> for the occurrence of the next one, in 69,163 AD. But I cannot confirm the previous one.</p>

CC BY-SA 4.0
2021-01-30T04:03:18.247Z
See this question: https://astronomy.stackexchange.com/questions/13227/are-there-ever-any-simultaneous-transits-of-both-mercury-and-venus-as-seen-from
Nilay Ghosh
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2021-01-30T04:51:51.037Z
@NilayGhosh That question does not give the answer I'm looking for here, even though it is also about simultaneous transits
Johansson McFleppers
CC BY-SA 4.0
2021-01-31T09:47:35.327Z
(1) That's wikipedia for ya. The first reference is unlinked and is from a non-academic site (Sky & Telescope). The second reference does not support the claim. It lists Mercury transits for a span of seven centuries. (2) All numerical integration techniques degrade in accuracy as time progresses forward or regresses backward. Predictions of transits are extremely sensitive to errors. Claims of transits that occurred 373 thousand years ago are beyond udicrous, at least to me.
David Hammen
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2021-02-01T18:32:06.347Z
@DavidHammen I don't know anything about this, but OP's peer-reviewed source searched 300,000 years into the future and 280,000 years into the past and they seem fairly confident in what they found, so extending that by another 33% might be possible. The claim was added by user Savage84, who [only made transit-related edits](https://en.wikipedia.org/wiki/Special:Contributions/Savage84) and often cited savage-garden.org, a now-defunct website that cited [SOLEX](http://www.solexorb.it/SolexOld/) as a source. I bet it was original research by Savage84, but it *may* be correct.
benrg
CC BY-SA 4.0
2022-02-02T01:13:40.187Z
@DavidHammen I dug up the issue of S&T and they reference [Jean Meeus and Aldo Vitagliano](https://ui.adsabs.harvard.edu/abs/2004JBAA..114..132M/abstract) in the June 2004 Journal of the British Astronomical Association [electronic ref to S&T](https://skyandtelescope.org/astronomy-resources/astronomy-questions-answers/will-mercury-and-venus-ever-transit-the-sun-simultaneously/) no mention of to the BC date
GrapefruitIsAwesome
<venus><planetary-transits><mercury>
Did simultaneous transits of Mercury and Venus actually last occur in 373,173 BC?
Johansson McFleppers
# Did simultaneous transits of Mercury and Venus actually last occur in 373,173 BC?

(Asked by: username_0 on 2021-01-30)

According to the Wikipedia article for [Transit of Venus](https://en.wikipedia.org/wiki/Transit_of_Venus#Grazing_and_simultaneous_transits), the last time a transit of Mercury and a transit of Venus occurred at the same time was 22 September of 373,173 BC. This is a Featured Article and the statement has been on the page since December 2008, implying authenticity. But I cannot find an academic citation anywhere to back this up.

I *can* find an [academic citation](http://adsabs.harvard.edu/full/2004JBAA..114..132M) for the occurrence of the next one, in 69,163 AD. But I cannot confirm the previous one.

**Tags:** venus, planetary-transits, mercury

> **Comments:**
> **username_1**: See this question: https://astronomy.stackexchange.com/questions/13227/are-there-ever-any-simultaneous-transits-of-both-mercury-and-venus-as-seen-from  
> **username_0**: @username_1 That question does not give the answer I'm looking for here, even though it is also about simultaneous transits  
> **username_2**: (1) That's wikipedia for ya. The first reference is unlinked and is from a non-academic site (Sky & Telescope). The second reference does not support the claim. It lists Mercury transits for a span of seven centuries. (2) All numerical integration techniques degrade in accuracy as time progresses forward or regresses backward. Predictions of transits are extremely sensitive to errors. Claims of transits that occurred 373 thousand years ago are beyond udicrous, at least to me.  
> **username_3**: @username_2 I don't know anything about this, but OP's peer-reviewed source searched 300,000 years into the future and 280,000 years into the past and they seem fairly confident in what they found, so extending that by another 33% might be possible. The claim was added by user Savage84, who [only made transit-related edits](https://en.wikipedia.org/wiki/Special:Contributions/Savage84) and often cited savage-garden.org, a now-defunct website that cited [SOLEX](http://www.solexorb.it/SolexOld/) as a source. I bet it was original research by Savage84, but it *may* be correct.  
> **username_4**: @username_2 I dug up the issue of S&T and they reference [Jean Meeus and Aldo Vitagliano](https://ui.adsabs.harvard.edu/abs/2004JBAA..114..132M/abstract) in the June 2004 Journal of the British Astronomical Association [electronic ref to S&T](https://skyandtelescope.org/astronomy-resources/astronomy-questions-answers/will-mercury-and-venus-ever-transit-the-sun-simultaneously/) no mention of to the BC date  

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## 0 answers

