According to Copernicus's heliocentric model, what is at the center of the universe?

In Copernicus's heliocentric model, the sun is placed at the center of the universe. This revolutionary idea shifted the perspective from the geocentric model, which positioned the Earth as the central body around which all celestial bodies revolved. By placing the sun at the center, Copernicus provided a more straightforward explanation of the observed movements of the planets and other celestial phenomena, aligning better with the phase observations of planets and their retrograde motion.

This model was significant as it laid the groundwork for modern astronomy and challenged the long-held beliefs of an Earth-centered universe. By conceptualizing the sun as the central body, it led to further insights by later astronomers like Kepler and Galileo, ultimately transforming our understanding of the solar system and the universe as a whole.