Copernicus took mathematics and painting college, even though he ended up making discoveries in astronomy. He is known to be the father of modern astronomy because of his theory that the sun was in the middle of the universe, not the Earth. His theory was published in 1543, and this theory is called the Heliocentric Theory. Copernicus wrote down his ideas in "De revolutionibus orbium coelestium", and the roman catholic church had banned this book f0r about 300 years. He did not make his observations by looking in the sky, but looking at ancient astronomy. One idea in Copernicus's theory was that three moons orbited Jupiter. In 1609, Galileo looked through his telescope and proved that three moons did indeed orbit Jupiter, which was the first proof of Copernicus's theory. Copernicus's theory was taught in universities in the 1500's eventhough it was not spread about the academic world until the 1600's.
Fearing the church, Copernicus's theories and findings were not published until after his death. The astronomer Kepler proved Copernicus correct using long and difficult mathematics. What motivated Copernicus to figure out whether or not if Earth was indeed in the center of the universe or not was becasue of Artistotle's geocentric theory. This theory stated that Earth was in the center of the universe, not the sun. Copernicus believed we were always in motion, eventhough it did not feel like it. Copernicus also believed that the size of each planet's orbit depended on their distance from the sun, and Earth made one orbit every year and rotated daily. Copernicus was the first person to make a complete and general system. He combined physics, mathematics, and cosmology all to form this system.