Ancient astronomers managed to turn fears of monsters eating the moon into a clear model of why and how total solar eclipses happen.
Babylonian astronomers were among the first to predict when an eclipse would happen. Their inscriptions on cuneiform tablets remain at museums. The Greeks later expanded the knowledge that would lead Isaac Newton to his theory of universal gravitation.
Eclipses continue to be the subject of curiosity. When the total solar eclipse turns day into darkness Aug. 21, scientists will be gathering data to continue to answer questions about the unusual celestial event.
Steve Clarke, the director of the heliophysics division at NASA said the eclipse will be one of the best-observed eclipses to date.
"We plan to take advantage of this unique opportunity to learn as much as we can about the sun and its effects on Earth," Clarke said in a statement.
Here are a few of the most important findings after observing a solar eclipse:
Greek astronomer Hipparchus of Nicaea estimates the distance from the earth to the moon by using the position of its shadow during a solar eclipse.
May 22, 1724
Giacomo Filippo Maraldi, an italian-born French astronomer, provided evidence that the corona is part of the sun, because the moon traverses the corona during a solar eclipse.
July 28, 1851
Robert Grant and William Swan and Karl Ludwig von Littrow determine that solar prominences are part of the sun because the moon is seen to cover and uncover them as it moves in front of the sun.
George B. Airy is the first to describe the sun's chromosphere: he calls it the sierra, thinking that he is seeing mountains on the sun, but he is actually seeing small prominences hat give the chromosphere a jagged appearance.
July 18, 1860
Warren De La Rue and Angelo Secchi use photography during a solar eclipse to demonstrate that prominences are part of the sun, because the corona looks the same from sites 250 miles apart.
Dec. 12, 1871
Jules Janssen uses spectroscopy to propose that the corona consists of both hot gases and cooler particles and hence is part of the sun.
May 29, 1919
Arthur S. Eddington confirm the bending of starlight by gravity as predicted by Einstein in his general theory of relativity, after observing a total solar eclipse from Principe and Brazil.
June 30, 1973
John Beckman used a Concorde supersonic passenger jet flying at 1,250 miles per hour over Africa to extend the duration of solar eclipse totality to 74 minutes--10 times longer than can ever be observed from the ground.