In 1610, Galileo pointed a small telescope at Jupiter and saw four moons orbiting it — a direct contradiction of the idea that everything in the universe orbited Earth, and a moment that did more to end one model of the cosmos than any written argument had managed

In January 1610, Galileo Galilei pointed a small telescope at Jupiter and saw something no one had ever recorded. Four faint points of light sat in a line beside the planet, and over the following nights they moved, shifting from one side of Jupiter to the ot…