In January of 1610, Galileo Galilei turned a new 30x telescope of his own manufacture to the heavens, specifically to view the “wandering star” Jupiter. What he saw must have been astonishing, even if he was already looking for evidence to support the heliocentric model of the solar system. Three small “stars” that had previously never been seen were in a line through Jupiter, and, as he continued his nightly observations, these tiny stars moved. One night, he saw one star disappear and on another night, reappear. These tiny stars appeared to be orbiting Jupiter.