The History and Reemergence of Planet X
Feb 05, 2016
In 1846 when there were only eight known planets, French mathematician Urbain Le Verrier predicted from the irregularities in Uranus's orbit that another giant planet was out there somewhere. Then in September of that same year astronomers from the Berlin Observatory made telescopic confirmation of Neptune (which had actually been sighted earlier by the likes of Galileo and other scientists although they were not sure what they spotted).