Galilean moons

Four largest moons of Jupiter

The Galilean moons, or Galilean satellites, are the four largest moons of Jupiter. They are, in descending-size order, Ganymede, Callisto, Io, and Europa. They are the most readily visible Solar System objects after Saturn, the dimmest of the classical planets; though their closeness to bright Jupiter makes naked-eye observation very difficult, they are readily seen with common binoculars, even under night sky conditions of high light pollution.

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