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
Ganymede (moon) the expansion continued, but some of the angular moment was transferred to Europa as the resonance caused its orbit to expand as well; the process continued until Europa encountered the 2:1 resonance with Ganymede. Eventually the drift rates of conjunctions between all three moons were synchronized and locked in the Laplace resonance. Ganymede is the largest and most massive moon in the Solar System. Its diameter of 5,268 km is 0.41 times that of Earth, 0.77 times that of Mars, 1.02 times that of Saturn's Titan (the second-largest moon), 1.08 times Mercury's, 1.09 times Callisto's, 1.45 times Io's and 1.51