Edmund Halley’s Famous Prediction

The first known observation of Halley’s Comet, or Comet Halley, took place in 239 BCE., when Chinese astronomers recorded its passage in the Shih Chi and Wen Hsien Thung Khao chronicles. When Halley’s returned in 164 BCE. and again in 87 BCE, it was noted in Babylonian records.  It’s also thought that another appearance of the comet in 1301 could have inspired Italian painter Giotto’s rendering of the Star of Bethlehem in “The Adoration of the Magi.”  The most famous appearance occurred shortly before the 1066 invasion of England by William the Conqueror. It is said that William believed the comet heralded his success. In any case, the comet was put on the Bayeux Tapestry — which chronicles the invasion — in William’s honor.  Astronomers in these times, however, saw each appearance of the comet as an isolated event and the appearance of comets were often foreseen as a sign of great disaster or change.

In 1705, Edmond Halley published his “Synopsis Astronomia Cometicae.” By using Sir Isaac Newton’s gravitational theories to chart the paths of two dozen comets, Halley hit on a provocative new theory: three comets seen in 1531, 1607 and 1682 were actually the same object. Halley argued that the comet orbited the sun and whizzed by the Earth roughly once every 76 years, and he predicted that it would reappear sometime in late 1758 or early 1759. “If it should return, according to our predictions,” he vowed, “impartial posterity will not refuse to acknowledge that this was first discovered by an Englishman.”  Unfortunately, Halley did not live long enough to see its return (he died in 1742).

His comet appeared in the sky on Christmas night of 1758, right on schedule. Its discovery was hailed as a triumph of scientific reasoning and Newtonian physics. “By its appearance at this time, the truth of the Newtonian Theory of the Solar System is demonstrated to the conviction of the whole world, and the credit of the astronomers is fully established and raised far above all the wit and sneers of ignorant men,” the British publication the Gentleman’s Magazine wrote. Shortly thereafter, the French astronomer Nicolas-Louis de Lacaille named the comet in Halley’s honor.

Halley’s comet will next appear in the night sky in the year 2062.