Copernicus put forth the idea of the heliocentric universe in his book De Revolutionibus Orbium Coelestium. Howevr, he was not the forts person to arote about it. The idea can be traced back almost two thousand years earlier to the Greek mathematician and philosopher Aristarchus of Samos (310-230 BC).
Johannes Kepler was born in Southern Germany in 1571, 28 years after the release of Copernicus’s discovery.
Kepler used Copernicus’s model as the foundation for his laws of planetary motion. Kepler accepted Copernicus’s heliocentric idea, but he also found parts of De Revolutionibus troubling. Kepler believed that earth and other know planets revolved around the sun, called the heliocentric model.
Elliptical orbits became Kepler’s first law, Kepler then added his Second Law each planet’s speed altered as a function of its distance from the sun. As a planet flew closer, it flew faster.
Kepler published his discoveries in 1609 and then spent the next 18 years calculating detailed tables of planetary motion and position for all six known planets.
Theory of planetary motion
