spase://CNES/NumericalData/CDPP-AMDA/Ephemerides/ganymede-orb-all

Ganymede orbits Jupiter at a distance of 1,070,400 km, third among the Galilean satellites, and completes a revolution every seven days and three hours. Like most known moons, Ganymede is tidally locked, with one side always facing toward the planet, hence its day is seven days and three hours. Its orbit is very slightly eccentric and inclined to the Jovian equator, with the eccentricity and inclination changing quasi-periodically due to solar and planetary gravitational perturbations on a timescale of centuries. The ranges of change are 0.0009–0.0022 and 0.05–0.32°, respectively. These orbital variations cause the axial tilt to vary between 0 and 0.33°. Ganymede participates in orbital resonances with Europa and Io: for every orbit of Ganymede, Europa orbits twice and Io orbits four times. The superior conjunction between Io and Europa always occurs when Io is at periapsis and Europa at apoapsis. The superior conjunction between Europa and Ganymede occurs when Europa is at periapsis. The longitudes of the Io–Europa and Europa–Ganymede conjunctions change with the same rate, making triple conjunctions impossible. Such a complicated resonance is called the Laplace resonance.