What Solar Eclipses Have Taught Us About the Universe

Total solar eclipses like the one that will cross the U.S. on Aug. 21 have captured the attention of astronomers throughout history — and have often led to advances in our understanding of how the universe works. Astronomers have been studying solar eclipses for centuries. In the late 16th and early 17th centuries, Danish astronomer Tycho Brahe and his apprentice German astronomer Johannes Kepler studied eclipses to try to arrive at a rough estimate of the moon's diameter.