What astronomer found that planets do not move in circles?

Actually Nicholas Copernicus did, but he was afraid unlike Galileo Galilei and Nicholas published his findings when he was close to death he knew his beliefs would get him in trouble with the Roman Catholic Church. Galileo did make a telescope and discovered Jupiter had moons that went around it and used it as proof. In the end of his life when he was older he was put under house arrest. His assistant was able to trick the guards and smuggle his book to get published.