"the Medicean stars"
by cm

The Galilean Moons
Public DomainThe Galilean Moons - Credit: NASA
The Galilean moons are the four largest of the 63 confirmed Jovian moons.   When Galileo discovered them in 1610, they were the first objects known to orbit a body other than the Earth or Sun.   They are named after lovers of Jupiter/Zeus: Io, Ganymede, Callisto and Europa.