On this date, in his amateur observatory seventy miles from Paris, Edmund Lescarbault, a French doctor, observed a small dark body transit the Sun. Leading French astronomer Urbain Le Ferrier checked Lescarbault's calculations and on January 2, 1860 announced the discovery of the planet Vulcan, a body between Mercury and the Sun, that had been hypothesized for decades. Later science proved Vulcan did not exist but it remained in literature as a handy fictional planet, including its role as the home planet of Gene Roddenberry's Star Trek character Spock. (By John Osborne)
Source Citation
David Andrew Weintraub, Is Pluto a Planet?: A Historical Journey Through the Solar System (Princeton, NJ: Princeton University Press, 2007), 124-125