Laplace-P that would have studied the Jovian moon system as well as the planet Jupiter. The orbiter would have done several flybys of other Jovian moons before being placed in orbit around Europa. The lander would have researched the ocean underneath the ice sheet of Europa. However, to avoid the damaging effects of Jupiter's radiation belts, the destination of the lander was switched in 2011 from Europa to Ganymede. Ganymede is the largest moon in the Solar System and has an internal ocean that may contain more water than all of Earth's oceans together. The orbiter would perform 13 flybys of
Solar System icy objects. Astronomers sometimes informally divide this structure into separate regions. The inner Solar System includes the four terrestrial planets and the asteroid belt. The outer Solar System is beyond the asteroids, including the four giant planets. Since the discovery of the Kuiper belt, the outermost parts of the Solar System are considered a distinct region consisting of the objects beyond Neptune. Most of the planets in the Solar System have secondary systems of their own, being orbited by planetary objects called natural satellites, or moons (two of which, Titan and Ganymede, are larger than the planet Mercury), and, in