Biography
Galileo Galilei (1564–1642) was an Italian astronomer, physicist, and polymath who played a significant role in the scientific revolution. He is known for his improvements to the telescope and consequent astronomical observations, and for his support of Copernican heliocentrism.
Contributions
Galileo made improvements to the design of the telescope, allowing for greater magnification. This enabled him to make groundbreaking observations: he discovered four moons orbiting Jupiter, observed the phases of Venus, and discovered sunspots on the sun, among other achievements.