Vulcan (hypothetical planet) Vulcan (hypothetical planet) Vulcan is a small hypothetical planet that was proposed to exist in an orbit between Mercury and the Sun. Attempting to explain peculiarities of Mercury's orbit, the 19th-century French mathematician Urbain Le Verrier hypothesized that they were the result of another planet, which he named "Vulcan". A number of reputable investigators became involved in the search for Vulcan, and despite occasional claimed observations, no such planet was ever confirmed. Peculiarities in Mercury's orbit have now been explained by Albert Einstein's theory of general relativity. Searches of data gathered by NASA's two "STEREO" spacecraft have failed to find
Terminus (planet) mental attacks. Terminus (planet) Terminus is a fictional planet at the edge of the Galaxy in Isaac Asimov's "Foundation Series", home of the Foundation (later capital of the Foundation Federation). Terminus is the sole planet orbiting an isolated star. Its nearest inhabited neighbor is Anacreon, 8 parsecs (26 light years) away, and it lies approximately 10,000 parsecs from the capital of the First Galactic Empire, Trantor, near the galactic center. There are almost no visible stars in its sky, only the huge lens of the Milky Way Galaxy. The nearby stars of the Province of Anacreon are known as "The