Original sentence: In 1600, astronomers were engaged in a great debate between the Copernican system (the planets revolved around the Sun) and the geocentric system (the planets and Sun revolved around Earth).In 1604, Galileo announced his support for the Copernican school of thought, but he lacked the means to reinforce the opinion
Edited sentence: He believed in Copernicus' theories leading him to search for evidence that the Sun was in the center of the solar system and not the Earth