He Deciphered the Solar System's Secrets

Today is the 425th anniversary of the birth of Johannes Kepler, a German astronomer who profoundly influenced modern science with his laws of planetary motion, published in 1609. Kepler's laws state that the planets in our solar system travel in elliptical orbits around the sun, that they move more quickly when nearer the sun, and that their orbital velocity is inversely proportional to their distance from the sun. These ideas laid the groundwork for Newton's theory on gravity, published 78 years later. Kepler also wrote the first science fiction story, which described a man's trip to the moon.

Posted in Space