Laws of Planetary Motion

Johannes Kepler, the son of a mercenary soldier and an innkeeper's daughter, was born prematurely just 2 days after Christmas 1571, in Weil der Stadt in Wurttemburg (now part of Germany). Danish astronomer Tycho Brahe became so impressed with his work that in 1600, he invited Kepler to become his assistant. Brahe, the mathematician at the court of Emperor Rudolph II at Prague, was one of the most prolific observers of the cosmos.

At the time of Brahe's death, one year after Johannes Kepler became his assistant, the data he collected during his lifetime was far superior to any others made prior to the invention of the telescope. Johannes Kepler stepped into his role of imperial mathematician and court astronomer. He remained in this position until he became mathematician to the states of Oberosterreich (upper Austria) in 1612.

During his working years, Johannes Kepler was a brilliant astronomer and mathematician and a prolific writer. Considered a founder of modern astronomy, Kepler may have been best known for formulating his famous three Laws of Planetary Motion.