Jupiter is the biggest planet in our Solar System, but only the biggest, also it has the biggest mass by far from all the planets. Because of its very big mass Jupiter has a very strong gravitational pull. The strong gravitational pull contributes to the attraction and keeping of lots of bodies that can not escape it, instead they revolve around the planet. These objects, or space bodies, that the gravitational pull of the planet managed to trap, became the moons, or rather natural satellites, of Jupiter.
