A few are. The rest are not.
The Galilean moons are Io, Europa, Ganymede, and Callisto, all of which orbit Jupiter. The term "Galilean" does not denote anything special about the moons other than that they were discovered by the astronomer Galileo Galilei.
Because they were discovered first by Galileo.
The Galilean moons orbit Jupiter.
The Galilean moons were discovered by Galileo Galilei in 1610.
No. It is a moon of Mars. The Galilean moons are moons of Jupiter.
No. There are four Galilean moons: Io, Europa, Ganymede, and Callisto.
They were discovered by Galileo.
They're fairly big for moons, although Jupiter itself is big. The four "Galilean" moons of Jupiter were the first "moons" other than our own Moon to be seen, by Galileo using his new telescope.
Four of the moons of Jupiter (Ganymede, Callisto, Io, and Europa) are larger than Pluto, but there are only 7 moons in this solar system that are larger than Pluto.
Callisto is composed of rock and ice and is the least dense of the Galilean moons.
The Galilean moons are the four largest moons of Jupiter, so called because they were discovered by Galileo Galilei.
Callisto - a moon of Jupiter is way smaller than the Earth. It is about 0.378 the size of Earth