At nearly the same time, an Italian by the name of Galileo Galilei was using a new invention—the telescope—to examine the night sky closely for the first time. What Galileo discovered, by observing the moons around Jupiter, was that there existed celestial bodies that orbited something other than the Earth.

Galileo was strong proponent of the Copernican model, and his publications eventually landed him under permanent house arrest for heresy. The Copernican model conflicted with the teachings of the Church at the time, namely that the Earth was the center of the universe, and that everything revolved around it.

In 1992, Pope John Paul II officially absolved Galileo of his crimes against the Church, 350 years after his death.