Copernicus was going up against everything and everyone, namely the Church. Copernicus would put forth the idea the heliocentric universe. This meant that the sun was at the center and not the earth. This could be taken to mean (and was by many) that God had not placed Man at the Center of the Universe. The idea that there was more that could occupy God than our existence and we were not the most important creature or thing was mind blowing.
