The Galileo affair, in which Galileo Galilei came into conflict with the Catholic Church over his support of Copernican astronomy, is often considered a defining moment in the history of the relationship between religion and science.

In 1610, Galileo published his Sidereus Nuncius (Starry Messenger), describing the surprising observations that he had made with the new telescope. These and other discoveries exposed major difficulties with the understanding of the heavens that had been held since antiquity, and raised new interest in radical teachings such as the heliocentric theory of Copernicus.

In reaction, many scholars attacked the theory because it seemingly contradicted several passages of Scripture. Galileo's part in the controversies over theology, astronomy and philosophy culminated in his trial and sentencing in 1633 on a grave suspicion of heresy.

source: Wikipedia