Galileo was born February 15th in 1564. He was an Italian astronomer, mathematician, physicist, philosopher and professor who made pioneering observations of nature with long-lasting implications for the study of physics. He also constructed a telescope that lead to his work on the Copernican theory, which supports a sun-centered solar system. In July 1609, Galileo developed his own telescope, his ambition pushed him to go further, he made the fateful decision to turn his telescope toward the heavens. Using his telescope to explore the universe, Galileo observed the moon and found Venus had phases like the moon, proving it rotated around the sun, which refuted the Aristotelian doctrine that the Earth was the center of the universe. He also discovered Jupiter had revolving moons that didn’t revolve around planet Earth.