What is the Planet Vulcan?
Planet Vulcan, aside from being the fictional planet in Star Trek which Spock comes from, is a hypothetical planet that many astronomers in the 19th century believed may have existed. This planet was supposed to have a low mass and be closer to the Sun than Mercury, so close that the telescopes of the day could not resolve it due to the overwhelming brightness of the Sun itself. Planet Vulcan, if it existed, could have surface temperatures even hotter than that of Mercury, which peaks at 700 degrees K (801 degrees F), maybe over a thousand degrees. The reason astronomers inferred that Planet Vulcan was likely to exist was due to discrepancies in the orbit of Mercury, detected by the French mathematician Urbain Jean Joseph Le Verrier in 1840-1843 when he was trying to predict the planet’s motion based on Newton’s theories. The procession of its perehelion (the point at which it is closest to the Sun) around its orbit was about 43 arcseconds per century off from what Newton’s theories wo
