This is a question for the astronomers of the modern day world?

Everyone knows who Capernicus is and that he is know for stating that the sun is the center of the universe. I know that this discovery/theory went against the church because they believed that the earth was the center of the universe. So my question is that Galileo later concurred with the Capernicus theory and he was facing heresy. So another astronomer, Johannes Kepler, also adopted the Capernican model for the universe but why didn't he WORRY about getting the Pope's approval when he decided to support Capernicus theory???