What is the significance of the four Galilean moons of Jupiter?

The Galilean moons of Jupiter are named after the Italian astronomer Galileo Galilei, who discovered them in 1610 using a telescope. The four Galilean moons of Jupiter are Io, Europa, Ganymede, and Callisto. They are significant because they are the largest and most massive moons of Jupiter, and they also have unique features and characteristics.

Io is known for its active volcanoes, which make it the most geologically active object in the solar system. Europa is believed to have a subsurface ocean and may have the potential to support life. Ganymede is the largest moon in the solar system and is the only moon known to have its own magnetic field. Callisto is the most heavily cratered object in the solar system and has a very old and unchanging surface.