January 7

Moon Discovery Changes Ideas about Universe

On this day in 1610, the Italian astronomer Galileo made one of the most important discoveries in the history of astronomy. He found three moons orbiting around the planet Jupiter. This discovery was important because it was the first evidence that not everything in the universe revolves around the Earth. During Galileo's time, Galileo was criticized by religious and government officials for challenging the geocentric (Earth at the center) theory of the universe.