The influential figure known for their contributions to the field of astronomy during the Renaissance was Nicolaus Copernicus. His heliocentric model, which proposed that the Sun, rather than the Earth, was at the center of the universe, fundamentally changed the understanding of celestial mechanics. Published in his work "De revolutionibus orbium coelestium" in 1543, this theory challenged long-held Ptolemaic beliefs that placed the Earth at the center. Copernicus's ideas eventually laid the groundwork for the scientific revolution, influencing later astronomers like Galileo and Kepler. His bold shift in perspective marked a significant turning point in the history of science.