Galileo Observes Jupiter's Moons

Date: January 7, 1610 • Location: Rome, Italy

Through his telescope, Italian astronomer Galileo Galilei made the first observation of Jupiter's Galilean moons: Io, Europa, Ganymede and Callisto, although he was not able to distinguish the first two until the following night.

Galileo di Vincenzo Bonaiuti de' Galilei, commonly referred to as Galileo Galilei or mononymously as Galileo, was an Italian astronomer, physicist, engineer and polymath. He was born in Pisa, then part of the Duchy of Florence. Galileo has been called the father of observational astronomy, classical physics, the scientific method, and modern science.