On November 30th, 1609, more than 400 years ago today, Galileo Galilei pointed his homemade “spyglass” at the moon. That night, he found himself staring at something that would change the way astronomers viewed the solar system forever.
Before Galileo took his famous close-up of our rocky satellite, the moon (like all celestial bodies) was thought to be just a glowing sphere in the sky. In fact, the Bible described it as another light—a dimmer version of the Sun*—before it was known that the moon merely reflected sunlight. But what Galileo saw was not a smooth sphere at all. Looking at the transition between the light and dark sides, he saw a jagged, pock-marked landscape. He knew at that moment that he was seeing craters and mountains on the moon, and he quickly set to sketching what became one of the first drawings of another astronomical body.
I can only imagine what it was like to look upon the Moon and sketch those craters for the first time. Having grown up knowing what the surface of the moon is like, one forgets how Earth-shattering (pardon the pun) the observation must have been.
*his observation was one of the first affronts in what became a long line of troubles with the catholic church.