  Understanding the origin of the orbital resonances of the Galilean satellites
of Jupiter will constrain the longevity of the extensive volcanism on Io, may
explain a liquid ocean on Europa, and may guide studies of the dissipative
properties of stars and Jupiter-like planets. The differential migration of the
newly formed Galilean satellites due to interactions with a circumjovian disk
can lead to the primordial formation of the Laplace relation n_1 - 3 n_2 + 2
n_3 = 0, where the n_i are the mean orbital angular velocities of Io, Europa,
and Ganymede, respectively. This contrasts with the formation of the resonances
by differential expansion of the orbits from tidal torques from Jupiter.
