During Copernicus' time, the Catholic Church was one of the ruling forces in the world. They did not take kindly to the idea that the Earth, home to God's own people, was not the center of the universe. The Church felt that the older, Aristotelian model was more in keeping with the Bible's idea of God's creation.
Astronomer Galileo discovered that he agreed with Copernicus' findings. Galileo had observed the skies with new, better telescopes, and found that Copernicus' model was more logical than the out-of-date Aristotelian model. However, Galileo did not go unpunished for his beliefs. He was put under trial, and had to write a retraction of his statement that supported Copernicus.