What are the unique characteristics of the Galilean moons discovered by Galileo Galilei?

Oh honey, buckle up! The four Galilean moons discovered by old pal Galileo are Io, Europa, Ganymede, and Callisto. These bad boys are known for their volcanic activity (looking at you, Io), icy surface oceans (hi there, Europa), and being bigger than some actual planets (shoutout to you, Ganymede and Callisto). Imagine having moons that are more extra than a reality TV star, but hey, that's space for you! üåå‚ú®