JUPITER'S FOUR MAIN MOON'S

                       JUPITER'S FOUR MAIN MOON'S

Of Jupiter's 63 moons, four can be viewed from Earth through binoculars. These moons were first discovered by Galileo Galilei, looking through a newly refined telescope around 1610, and  they still are called the Galilean moons. Galileo was astonished to find that these four moon -Ganymede, lo, Europa  and Callisto form a perfect line with the planet. Each has its own these  four moons- low distinctive features.
             With more than 150 volcanoes, lo. is the most geologically active moon in the solar system. Europa has an icy surface that may cover liquid water, of- fering  the possibility that we may one day discover some kind of life-form there. Ganymede is the largest  moon at in the solar system, larger even than lo, the Earth's moon. Callisto, heavily  pockmarked, is the most cratered object in the solar system.