Vulcan, the planet
- Cause of death
- Killed by a successor
General relativity explained Mercury's orbit without needing an extra planet to explain it.
Mercury's orbit did not behave the way Newton said it should, so Urbain Le Verrier proposed a planet between Mercury and the Sun to account for the discrepancy. This was a reasonable bet: he had found Neptune the same way. Astronomers reported sightings for decades. Then Einstein published general relativity in 1915, the anomaly dissolved into the mathematics, and a planet that many people had personally observed stopped existing.
Replaced by General relativity.
Standing in the archive
Rank 32 of 127 by lifespan. Vulcan, the planet outlasted 75% of everything else on file.
Cite this entry
"Vulcan, the planet." How Long It Lasted, https://www.howlongitlasted.com/thing/planet-vulcan.
Died nearby
- Adobe Flash Playerabout 24 years · killed by a successor
- Amazon Dash Buttonabout 4 years · killed by a successor
- Apple AirPortabout 18 years · killed by a successor
- Betamaxabout 41 years · killed by a successor
- Blockbusterabout 28 years · killed by a successor
Sources
- Vulcan (hypothetical planet) — Wikipedia (archived)
- The Hunt for Vulcan, the Planet That Wasn't There — National Geographic (archived)
Last checked by a human on 24 July 2026