Letter to Johannes Kepler

Most Excellent Kepler, I thank God that He has been pleased to make me the first observer of marvelous things unrevealed to bygone ages. I have observed that the planet Jupiter has four moons which revolve about it, just as our Moon revolves about the Earth. Through my telescope, I have seen what no man before has witnessed - mountains on the Moon, countless stars invisible to the naked eye, and these celestial bodies orbiting Jupiter. This proves beyond doubt that not all heavenly bodies revolve around the Earth. I have faced much opposition from those who refuse even to look through my telescope, preferring ancient authority to observable truth. They say that what I report cannot be true because Aristotle did not mention it. How I wish these philosophers would apply their reason to the evidence before their eyes! Your work on planetary motion gives me great hope that truth will ultimately prevail over dogma. Together, we are witnessing the birth of a new understanding of the cosmos. Your devoted colleague, Galileo Galilei