PBS
Pbs Learning Media: Galileo: Discovering Jupiter's Moons
This video segment adapted from NOVA shows how Galileo, using his newly developed refracting telescope, observed four of Jupiter's moons, the first astronomical bodies to be discovered since ancient times.
Crash Course
Crash Course Astronomy #17: Jupiter's Moons
Before moving on from Jupiter to Saturn, we're going to linger for a moment on Jupiter's moons. There are 67 known moons, and 4 huge ones that we want to explore in greater detail. Ganymede is the largest - larger, in fact, than any...