1-157-986 - Oxford Science Archive/Heritage Images

Edmond Halley, English astronomer and mathematician, c1720 (1794). Edmond Halley (1656-1742), Astronomer Royal from 1720 until 1742, discovered the proper motions of stars and the periodicity of comets. He correctly calculated that the comets seen in 1531 and 1607 were the same objects that followed a 76 year orbit - the comet now know as 'Halley's Comet'. Unfortunately, Halley did not live to see his prediction come true when the comet returned on Christmas Eve 1758. After a portrait by Richard Phillips, painted soon after Halley became Astronomer Royal.