That Time Scientists Thought Vulcan Was A Real Planet

Zoomers and Millennials will always disagree about how many planets there really are. Sure, NASA now classifies Pluto as a dwarf planet, but all of the mnemonics I learned make no sense without it. My Very Eager Mother Just Served Us Nine ... WHAT? Nine what, Gen Z??

Surprisingly, this isn't the first time that humans have had to deal with the loss of a planet. You'd think we'd be able to keep track of how many massive rocks there are floating around our nearest star, but it's proven shockingly difficult to nail down. In the 19th century, we gained and lost a planet that we never even had to begin with.

It all started because astrophysicists are good at math. Very good at math, and in this case, too good. You see, in 1840, the head of the Paris Observatory suggested to a young mathematician named Urbain Le Verrier that he make a model of Mercury's orbit based on Newtonian physics. Le Verrier spent five years making a meticulous model working off previous observations, and the Paris Observatory agreed to verify his predictions when Mercury passed by the sun three years later. Unfortunately for Le Verrier's model, Mercury behaved slightly differently than expected.

Undeterred, Le Verrier made a new model over the course of the next decade, considered so rigorous that any deviation from it would be taken as proof that something was interfering with Mercury's orbit. Sure enough, when Mercury was next observed, it varied from Le Verrier's model by 43 arcseconds, and Le Verrier and the astronomical community agreed that there was either another planet between Mercury and the sun or an asteroid field of comparable gravitational pull to a planet.

You may be thinking about the last time you tried to figure out the tip on a big bill and wonder why the hell everyone was so convinced when Le Verrier was off by such a tiny margin. After all, people do bad math all the time; surely you'd just chalk it up to a small rounding error and move along? Maybe for other mathematicians, that would be feasible, but in 1846 Le Verrier had discovered the planet Neptune based on similar discrepancies in Uranus' orbit.

At this point, if Le Verrier had made a yo-mama joke to explain a planetary wobble, it would have been published widely. With astronomers forced to admit that yo mama, while not particularly large, may be dense enough to produce such gravity.

Once Le Verrier announced his suspicions about a phantom planet, he received anecdotal evidence from an amateur astronomer detailing a small black dot seen transiting the sun, which, after thorough interrogation, Le Verrier agreed must be this new planet. Le Verrier announced this new planet in 1860 and gave it the name Vulcan after the Roman god.

When another French astronomer disputed the claim that this planet had passed the sun, Le Verrier doubled down and published Vulcan's theoretical path and orbit and received a flurry of reports from amateur astronomers claiming to verify his predictions. Over the next 40 years, amateurs and experts alike sought Vulcan in its tiny orbit around the sun. 

In 1908 a harsh blow was dealt to claims of Vulcan's existence when photographic evidence from a total solar eclipse failed to show any intra-Mercurial planets. The final blow came in 1915, as Einstein's theory of relativity changed how we think about gravity and resolved the small discrepancies in Mercury's orbit. Rip Vulcan (1859-1915). Math brought it into this universe, and math can bring it right back out.

Despite this, there's still some evidence that Vulcan may have existed, including photographic and video evidence of life that's hard to deny. Explain this, Einstein:

Top Image: Library Of Congress