Born Oct. 29, 1656, in Haggerston, near London; died Jan. 14, 1742, in Greenwich. English astronomer and geophysicist. Studied at Oxford University and became a member of the London Royal Society in 1678. Became a professor of mathematics at Oxford University in 1703 and director of the Greenwich Observatory in 1720.

In 1676-78, Halley compiled the first telescopic catalog of 341 stars in the southern sky; he discovered the first periodic comet (Halley’s comet, 1682) and predicted its return in 1758. In 1718 he discovered the proper motion of stars, and in 1720-38 he discovered new perturbations in the motion of the moon and the planets. As a result of his expeditions (1698-1700) he compiled the first detailed geomagnetic map (1701). He was the first to publish (at his own expense) I. Newton’s Mathematical Principles of Natural Philosophy. He translated from Arabic and published (1710) the mathematical works of Apollonius of Perga.