On January 7, 1610, physicist and astronomer Galileo Galilei turned his new telescope to the nocturnal sky to watch the planet Jupiter and discovered the eponymous four moons of Jupiter, Io, Europa, Ganimede, and Callisto.
On January 7, 1610, physicist and astronomer Galileo Galilei turned his new telescope to the nocturnal sky to watch the planet Jupiter and discovered the eponymous four moons of Jupiter, Io, Europa, Ganimede, and Callisto.