How were the contributions of Nicolaus Copernicus and Galileo Galilei?

Nicolaus Copernicus revolutionized astronomy with his heliocentric model, proposing that the sun, rather than the Earth, is at the center of the universe, which challenged long-held geocentric views. Galileo Galilei further advanced this paradigm by using a telescope to make astronomical observations, such as the moons of Jupiter and the phases of Venus, providing empirical evidence supporting the heliocentric theory. Together, their contributions laid the groundwork for modern astronomy and significantly altered humanity's understanding of its place in the cosmos.