Although Copernicus was right about a few things, he was wrong about the idea of the Sun being the center of the universe and being motionless because in fact the Sun did move as well as the stars. Also, Ptolemy and Copernicus both believed the orbits of the planets were circular, but they were actually elliptical. While the Ptolemy’s geocentric model was really good at predicting planetary positioning, it wasn't accurate. Copernicus’s model explained the true motions of planets, using the motion of the Earth around the sun as a common aspect or cause while Ptolemy’s posed numerous separate causes to the motion of each planet due to him having to replicate Earth’s motion in relation to the Sun. While Ptolemy's model seemed to merely accommodate
