Галілеєві супутники Юпітера
In January 1610, Galileo Galilei observed Jupiter’s four largest moons: Io, Europa, Ganymede, and Callisto. At first they looked like tiny “stars” near the planet; repeated observations showed that they moved around Jupiter. This was the first discovery of moons orbiting a planet other than Earth.
The name “Galilean moons” honors Galileo, though German astronomer Simon Marius independently observed them around the same time and proposed the mythological names Io, Europa, Ganymede, and Callisto. Galileo published his observations in *Sidereus Nuncius* in 1610.