Galileo Galilei was born on February 15, 1564, in Pisa, Italy. His father, Vincenzo, was a well-known musician and insisted his children received a formal education. When he was 19 years old, Galileo began to study medicine at the University of Pisa. This also led him to study mathematics, physics and philosophy. In 1592, Galileo began his academic career as a professor at his alma mater.
In 1609, Galileo heard of a new invention that had been built by Dutch eyeglass makers. Never having seen one himself, he set out to build his own – a telescope. Unbeknownst to him, his invention improved greatly on the original. Galileo was able to see and observe the surface of the moon, follow the phases of Venus, and discovered four of the largest moons of Jupiter. Based on his findings, Galileo endorsed the Copernican theory that the sun was at the center of our solar system, and all the planets (including Earth) rotate around it. In 1616, the Church forbade him to teach as they saw his radical theories as a threat. Nearly 18 years later, Galileo was condemned for heresy and sentenced to permanent house arrest. Though he was unable to leave his home, Galileo continued to search the sky from his window. He also continued to theorize and create new knowledge regarding the “laws of motion and the principles of mechanics” (BBC). He passed away in Arcetri, Tuscany, Italy, on January 8, 1642.
Sources: BBC, Biography.com, Space.com