On This Day In History On This Day In History: Galileo Discovered Four Jupiter’s Moons – On Jan 7, 1610 MessageToEagle.com | January 7, 2017 MessageToEagle.com – On January 7th, 1610, four hundred years ago, Galileo Galilei, the Italian astronomer and mathematician made a discovery of the four Galilean moons: Ganymede, Callisto, Io Read More