On January 2, 1860, French mathematician Urbain Le Verrier announced the discovery of a new planet. Situated in the toasty region between Mercury and our star, what better name for this body than Vulcan?
Vulcan was the Roman god of all things hot — fire, forges, metalworking, deserts and, of course, volcanoes, to which he gave his name. He was literally thrown out of Olympus by his father Jupiter, falling into Mount Etna. He was said to labour away at his forge there, deep below the earth, and whenever his wife Venus was unfaithful, he would grow so angry that the sparks from his metalworking would shoot up out of the mountain.
Le Verrier had spent the 1840s and 1850s building a theoretical model of Mercury's orbit using classical mechanics – Sir Isaac Newton's laws of motion and gravitation. Unfortunately, observations of Mercury transiting the sun repeatedly showed a small but definite deviation from Le Verrier's predictions. The planet's perihelion, its closest point to the Sun, was shifting around the star a little bit faster than expected.
So Le Verrier hypothesized a body between Mercury and the Sun which was gravitationally affecting the former's orbit. This hypothesis was lent significant weight by Le Verrier's 1846 discovery of Neptune using the same method, deducing its existence from the perturbations of the neighbouring planet, in that case Uranus.
In late 1859, Le Verrier found his "proof" of Vulcan. Edmond Modeste Lescarbault, a physician and amateur astronomer, claimed to have observed an unknown body transiting the Sun. It appeared to orbit in a speedy 20 days at a distance of just 0.14 AU (13 million miles). Le Verrier made his announcement, and Lescarbault was awarded the Légion d'honneur, the highest order of merit in France.
But some were skeptical. For the next 55 years astronomers endeavoured to confirm Vulcan's existence, particularly during solar eclipses. Many claimed to see the planet, including some highly reputable astronomers. But no matter how much Le Verrier reworked his calculations, Vulcan never seemed to show up when it was predicted.
Finally, in 1915, the true reason for Mercury's accelerated perihelion precession was discovered. It was Newton's laws that were at fault. Einstein's newly published Theory of General Relativity, in which massive objects like the Sun cause spacetime itself to curve, explained Mercury's observed motions exactly.
The "real" Vulcan was dead, but the idea had a long life in it yet.
Planet of the Daleks
Vulcan appeared in numerous works of science fiction during the first half of the 20th century, including works by Ray Cummings and Leigh Brackett. Often it was portrayed as small, dense, and rich in minerals, with a thick atmosphere.
"Doctor Who" jumped on the Vulcan bandwagon in 1964. The series' menacing metal villains, the Daleks, had proved wildly popular — popular enough to warrant the publication of an anthology of short stories and comic strips called "The Dalek Book", written by David Whitaker and Terry Nation.
As the Daleks draw their plans to conquer the Solar System in one of the strips, their map is seen to include Vulcan between the sun and Mercury. Apparently, in this version of the "Doctor Who" universe at least, Le Verrier was right.
Two years later, Whitaker wrote the TV story "The Power of the Daleks" and used the name Vulcan again. The Doctor – newly regenerated for the very first time – must save a human colony from the Daleks on this desolate planet covered in bubbling mercury pools. But this Vulcan may be extrasolar; the 1993 novelisation of "The Power of the Daleks" places the planet many parsecs from Earth, out on the frontier.
And the frontier, specifically the final one, is where we find the most enduring version of the planet Vulcan.
Strange New World
"Star Trek" creator Gene Roddenberry originally conceived the Enterprise's science officer as a red-skinned humanoid from Mars. By the time cameras rolled, though, he was from Vulcan.
Spock (Leonard Nimoy) displayed emotions in the rejected pilot, "The Cage", but was quickly established in transmitted episodes as a strict adherent to logic. As the series (and franchise) went on, we learned that Vulcans suppressed their emotions or purged them altogether, and we discovered the wonders of the Mind Meld and the Nerve Pinch.
Spock was enormously popular with audiences, even more than the show's lead character, Captain Kirk (William Shatner). Coincidentally, Shatner had appeared in a 1964 "Outer Limits" episode as an astronaut on a Venusian mission called Project Vulcan. Amongst Shatner's co-stars was Lawrence Montaigne, who later cropped up in the "Star Trek" episode "Amok Time"… as a Vulcan.
"Amok Time" provided the series' first visit to the planet itself, revealed to be a desert with a red sky and thin atmosphere, where ancient rituals hold sway. Later visits in "Star Trek: The Motion Picture" and "The Next Generation" fleshed out the planet and its culture, while "Voyager" gave us a new regular Vulcan in the form of tactical officer Tuvok.
"Enterprise" took us back to the early days of Earth-Vulcan relations, leading up to the two planets becoming founding members of the Federation, as well as exploring Vulcan culture further through series regular T'Pol and even meeting the father of Vulcan logic, Surak.
J. J. Abrams may have destroyed Vulcan in the alternate timeline of his 2009 "Star Trek" film, but it lives on in the various new series of the last decade. "Discovery" recounted how the planet, now called Ni'Var, rejoined the Federation after a period of galactic devastation in the far future, while "Strange New Worlds" continues to fill in Spock's journey from the emotional lieutenant of "The Cage" to the logic-driven lieutenant commander of the Original Series.
Meanwhile, there was one more surprise in store. Spock's Vulcan orbits a real star, 40 Eridani A, about 16 light-years from Earth. A 2018 study of 40 Eridani A concluded that radial velocity variations in that star were likely caused by a planet orbiting it. Had the real Vulcan been found at last?
Sadly not. Like Le Verrier before them, the scientists had jumped to the wrong conclusion. Subsequent studies debunked the potential planet, and as of 2024 it has been generally accepted that the variations are purely down to stellar activity. The Astronomical Journal called it "The Death of Vulcan", but in fiction at least, Vulcan still prospers.
