Galileo Galilei is renowned for which accomplishment in astronomy?

Galileo Galilei is widely recognized for using a telescope to confirm the heliocentric theory, which posits that the sun is at the center of the universe, and the Earth, along with other planets, orbits around it. This was a significant shift from the previously accepted geocentric model, which placed the Earth at the center of the universe.

Galileo's advancements in telescope technology allowed him to make important astronomical discoveries, such as observing the moons of Jupiter, the phases of Venus, and sunspots. These observations provided strong evidence supporting the heliocentric theory, challenging the conventional views held at the time and contributing to the Scientific Revolution. His work laid the foundation for modern astronomy and significantly influenced scientific thought by providing empirical evidence that contradicted longstanding beliefs about the cosmos.