Multiple choice general knowledge history Galileo was an Italian astronomer who: Developed the telescope Discovered that the movement of the pendulum produces a regular time measurement. Discovered 4 satellites of Jupiter All are correct Reveal answer Fill a bubble to check yourself D Correct answer Explanation Galileo made all these contributions: he improved the telescope's design (though didn't invent it), discovered pendulum isochronism, and discovered Jupiter's four largest moons (Io, Europa, Ganymede, Callisto).