Guillaume le Gentil didn’t find purpose in the church, seeking it instead in the stars. In 1761, he participated in a global astronomical mission to observe the Transit of Venus from various stations across the globe. But the course of science never did run smooth, and le Gentil’s travels would scatter him far and wide, across time and space, and from toilet-bound depression to true illumination. The Something True season finale. Read a full transcript of this episode on the Something True website. Follow Something True on Twitter @atruepodcast. (Or just follow Duncan and Alex.) Music on this week’s episode: Chris Zabriskie – But Enough About Me, Bill Paxton* Lee Maddeford – Le petit jardin (with Les Gauchers Orchestra)* Dan Warren – Instrumental - Son of God* Jelsonic – Breeeze* Jahzzar – Silver * Scanglobe – Westerlund 1* David Szesztay – Sweeper Chris Zabriskie – John Stockton Slow Drag* Scott Holmes – Green Fields* *modified for the podcast.
Venus, the second planet from the sun brightest star in the earths night sky.
In 1627, the german astronomer Johannes Kepler realized it was possible to predict the transit of Venus, that rare moment when observing from Earth, Venus would appear to pass across the face of the sun.
And that was important because if you knew how long that took, you could determine the average distance from the earth to the sun.
And if you had that, you could measure the entire solar system.
The next visible transit of Venus, Kepler predicted, would be in 1631.
But just one year before that, Kepler died.
He did not get to see the transit, and neither did anybody else, because his notes were not very helpful.
But all was not lost.
Another astronomer, Jeremiah Horrocks, believed that, as a rule, transits of Venus occurred in pairs, eight years apart, so the next one should be in 1639.
He was right.
And in that year, he recorded the fabled transit and thus determined the distance between the earth and the sun inaccurately.
As it turned out, perhaps if hed had another chance, he would have been able to refine his first calculations.
But Horrocks had also discovered that after the transits in 1631 and 1639, there wouldnt be another.
For over a hundred years, transits came in pairs, but only once in a century, two close chances in a lifetime.
In 1716, the british astronomer Edmund Halley made a plan to observe the next transits in 1761 and 1769, which he himself would not live to see.
He called for excellent astronomers from a coalition of enlightened nations to be stationed at key points around the globe where they could gather as much data as possible on the transit simultaneously.
It would be a huge undertaking, requiring the cooperation of european nations, who were normally at constant war with one another.
But everyone recognized that the pair of transits coming up would be quite literally a once in a lifetime opportunity to unlock the secrets of the solar system.
The next ones wouldnt be until 1874 and 1882.
And who was going to observe those?