Synopsis of the Astronomy of Comets (1705)
Computed parabolic orbits of 24 comets and predicted the return of the 1682 comet in 1758
Science · Maths, astronomy, medicine & more
Edmond Halley
1656–1742 · English
Astronomy — comets and geophysics
Edmond Halley was an English astronomer, mathematician and geophysicist who became the second Astronomer Royal in 1720. He showed that the comets of 1531, 1607 and 1682 were one body and predicted its return in 1758, which duly happened after his death; the comet now bears his name. He also persuaded Isaac Newton to write the Principia and paid for its printing, catalogued southern stars from St Helena, and produced pioneering maps of winds and magnetic variation.
How to spot them
- ▸Predicted the return of the comet now named after him (seen again in December 1758)
- ▸Second Astronomer Royal, succeeding John Flamsteed in 1720
- ▸Urged Newton to write the Principia and paid for its publication
- ▸Star catalogue from St Helena; captained HMS Paramore on magnetic survey voyages
- ▸Britain's Antarctic research station is named after him
Key discoveries & works
Catalogue of southern stars observed from St Helena (1679)
Catalogus stellarum australium; positions of 341 southern-hemisphere stars
World map of the trade winds and monsoons (1686)
Often called the first meteorological map
Mortality tables for the city of Breslau (1693)
Early life tables, a foundation of actuarial science and annuity pricing
Charts of magnetic compass variation with lines of equal declination (1701)
Isogonic charts based on his voyages in command of HMS Paramore
Discovery of the proper motion of the 'fixed' stars (1718)
Comparing his positions with ancient catalogues showed Sirius, Arcturus and Aldebaran had moved
Transit of Venus method for measuring the Sun's distance (1716)
Proposed timing transits from widely separated places; used in the 1761 and 1769 transits
Key ideas
- Comets can travel in closed elliptical orbits and return periodically
- Stars are not truly fixed but have their own slow proper motions
- Transits of Venus could fix the astronomical unit, the distance from Earth to the Sun
- Proposed in 1692 a hollow Earth made of concentric shells to explain shifting magnetic readings
Quick-fire facts
- •Born 8 November 1656 at Haggerston, near London; died 14 January 1742 at Greenwich
- •Became Savilian Professor of Geometry at Oxford in 1704
- •Designed and tested an improved diving bell in the early 1690s
- •The comet was first sighted on its predicted return on Christmas night 1758 by the amateur Johann Palitzsch
- •Halley's Comet has a period of about 76 years; its last appearance was in 1986 and the next is due in 2061
- •The European Space Agency's Giotto probe flew past Halley's Comet in 1986
- •The British Antarctic Survey's Halley Research Station is named after him
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Sources
- MacTutor History of Mathematics, University of St Andrews — Edmond Halley
- Alan Cook — Edmond Halley: Charting the Heavens and the Seas