Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
July 6, 1996
Edmond Halley's Greatest Discoveries
Explanation: Sir Edmond Halley was quite a discoverer. Born in 1656, he computed in 1705 that a bright comet was periodic and would make another appearance in 1758. The comet appeared as predicted and is now known as Comet Halley. Unfortunately, Halley died in 1742 and never saw his prediction come true. In 1716 Halley proposed two types of diving bells that would enable people to explore the deep sea. Halley pioneered our understanding of trade winds, tides, cartography, naval navigation, mortality tables, and stellar proper motions. Halley (incorrectly) proposed that the Earth was made of concentric spheres the size of the inner planets each of which might contain life. Perhaps Halley's greatest discovery, however, was that his contemporary Isaac Newton had discovered a powerful mathematical formulation of gravity.
Authors & editors:
Robert Nemiroff
(MTU) &
Jerry
Bonnell (USRA).
NASA Technical Rep.:
Sherri
Calvo.
Specific rights apply.
A service of:
LHEA
at
NASA/
GSFC