Halley Edmond


Halley was born in 1656 in Hackney, near London, to a wealthy family. He was soon interested in astronomy, and in 1675 he felt confident enough to alert the Astronomer Royal, John Flamsteed, about errors in the ephemeris of Jupiter and Saturn. Impressed, Flamsteed helped him to publish his first scientific paper, then to sail to the island St. Helena where during a stay of 18 months between 1676 and 1678 he established the first catalog of the stars of the southern sky. Like most scientists of his time, he was interested in many subjects, including a diving bell and translating Arabic scientific texts. His astronomical work is important: He showed in particular how the transits of Venus across the Sun could be used to determine distances in the Solar system by observing the entry and exit of Venus across the solar disk at various locations around the globe. But his main interest was in comets, on which he conducted fundamental research. Halley published his results in 1705, first in Latin in a British scientific journal, the Philosophical Transactions of the Royal Society of London, and then in English in a book entitled A Synopsis of the Astronomy of Comets. This little book, which well deserves its title, contained a brief history of cometary astronomy. It also described Newton’s method to determine the orbits of comets, with practical examples, gave the orbital parameters of 24 comets and overall showed that the comets of 1531, 1607 and 1682 were one and the same object, of which he predicted the return 76 years later.

Esteemed by his colleagues for his many ideas, and also for his pleasant character, Halley was the first secretary of the Royal Academy of London ; as such, he published articles written by the members of the Academy. His old age was saddened by the idea that he would miss the next return of the comet he had studied — he would have been 102 years. He died in 1742 at the already respectable age of 85.

His glory was at its zenith when the comet reappeared as expected in 1758-1759; the astronomer and priest Nicolas Louis de La Caille (1713-1762) proposed to give it the name of Halley’s comet, which has remained.