Edmond Halley (1656 - 1742)

Edmond Halley was an English astronomer, interested primarily in observations of the Moon, the movements of planets, and the laws of gravity. He studied at Queen's College in Oxford, and after graduating in 1676, moved to the island of St. Helena, located in the South Atlantic Ocean, to observe stars in the Southern Hemisphere. After returning to England in 1678, he published Catalogus Stellarum Australium which roughly translates as Catalogue of Australian Stars which detailed the stars he had observed while down under. Science people liked giving their books Latin names!

Although contributing to many other scientific projects, Halley is most famous for predicting the return of a comet which later became known as Halley's Comet. He made observations of a comet in 1682. He noticed that this comet shared characteristics with one that had appeared in 1607 and another in 1531. He realised that these three comets might actually be the same one, and that approximately every 75-76 years it reappeared. He predicted that the comet would reappear again around 1758. Although he died 15 years beforehand, Halley's theory proved correct, and his comet was observed again in 1758, confirming that comets are actually objects that orbit the Sun. The fact that Halley was able to predict when his comet would appear meant that scientists could look through older observational records and find out when else the comet had been spotted. They discovered that ancient records from Chinese astronomers from possibly as far back as 240 BC showed that an object that they had observed was in fact Halley's Comet.