Edmund Halley

(1656 - 1742 AD)

English astronomer who established the first observatory in the southern hemisphere on the island of St. Helena. He became good friends with Newton and convinced him to publish the Philosophiae Naturalis Principia Mathematica. In his "Ode to Newton," with which he prefaced the Principia, he wrote "Nearer the gods no mortal may approach" (Westfall 1988). After studying comets, he noticed that the path of the comets of 1456, 1531, and 1607 were surprisingly similar. He surmised that these three sightings were different apparitions of a single comet, which he predicted would return again around 1758. He died before his prediction was tested, but the comet indeed returned and has been known as Halley's Comet ever since. When Flamsteed died in 1720, Halley was appointed Royal Astronomer at Greenwich Observatory.