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
The empire on which the sun never sets the sun encircles.” Mesopotamian texts contemporary to Sargon of Akkad (c. 2334 – 2279 BC) proclaim that this king ruled “all the lands from sunrise to sunset.” In the early 16th century, the phrase, ""el imperio en el que nunca se pone el sol"" ("the empire on which the sun never sets") originated with a remark made by Fray Francisco de Ugalde to Charles I, who as king of Spain and as Holy Roman Emperor by the name of Charles V, had an empire, which included many territories in Europe, islands in the Mediterranean and Atlantic, cities in North Africa