What happened on September 13 1610?

On September 13, 1610, the Italian astronomer Galileo Galilei made significant observations of Jupiter and its moons using a telescope he had improved. He discovered the four largest moons of Jupiter—Io, Europa, Ganymede, and Callisto—now known as the Galilean moons. This discovery provided strong evidence against the geocentric model of the universe, supporting the heliocentric theory that posited the Sun at the center of the solar system. Galileo's findings marked a pivotal moment in the Scientific Revolution, influencing the study of astronomy and our understanding of planetary motion.