2.3.1 spase://CNES/NumericalData/CDPP-AMDA/Ephemerides/europa-orb-all Europa 2018-10-14T11:46:29Z Europa orbits Jupiter in just over three and a half days, with an orbital radius of about 670,900 km. With an eccentricity of only 0.009, the orbit itself is nearly circular, and the orbital inclination relative to Jupiter's equatorial plane is small, at 0.470°. Like its fellow Galilean satellites, Europa is tidally locked to Jupiter, with one hemisphere of Europa constantly facing Jupiter. Because of this, there is a sub-Jovian point on Europa's surface, from which Jupiter would appear to hang directly overhead. Europa's prime meridian is the line intersecting this point. Research suggests that the tidal locking may not be full, as a non-synchronous rotation has been proposed: Europa spins faster than it orbits, or at least did so in the past. This suggests an asymmetry in internal mass distribution and that a layer of subsurface liquid separates the icy crust from the rocky interior. The slight eccentricity of Europa's orbit, maintained by the gravitational disturbances from the other Galileans, causes Europa's sub-Jovian point to oscillate around a mean position. As Europa comes slightly nearer to Jupiter, Jupiter's gravitational attraction increases, causing Europa to elongate towards and away from it. As Europa moves slightly away from Jupiter, Jupiter's gravitational force decreases, causing Europa to relax back into a more spherical shape, and creating tides in its ocean. The orbital eccentricity of Europa is continuously pumped by its mean-motion resonance with Io. Thus, the tidal flexing kneads Europa's interior and gives it a source of heat, possibly allowing its ocean to stay liquid while driving subsurface geological processes. The ultimate source of this energy is Jupiter's rotation, which is tapped by Io through the tides it raises on Jupiter and is transferred to Europa and Ganymede by the orbital resonance. spase://CNES/Person/NAIF PrincipalInvestigator jup-moons-orb PartOf Jupiter Moons spase://SMWG/Repository/CNES/CDPP-AMDA Online Open http://amda.cdpp.eu Text.ASCII SPICE spase://CNES/Instrument/CDPP-AMDA/Ephemerides Ephemeris 1970-01-01T00:00:05Z 2036-12-31T23:40:04Z PT20M Jupiter Jupiter.Europa xyz_jsm eur_jup_jsm Rj Cartesian JSM TimeSeries 3 x 1 eur_jup_jsm(0) y 2 eur_jup_jsm(1) z 3 eur_jup_jsm(2) Positional xyz_jso eur_jup_jso Rj Cartesian JSO TimeSeries 3 x 1 eur_sat_jso(0) y 2 eur_jup_jso(1) z 3 eur_jup_jso(2) Positional xyz_IAU_jupiter eur_jup_xyz Rj Cartesian IAU_Jupiter TimeSeries 3 x 1 eur_jup_xyz(0) y 2 eur_jup_xyz(1) z 3 eur_jup_xyz(2) Positional distance europa-jupiter eur_jup_r Rj TimeSeries Positional latitude IAU_jupiter eur_jup_lat deg Positional longitude IAU_jupiter eur_jup_lon deg Positional mlat eur_jup_mlat mlat=10.31°xcos(196.61°-lon_iau)+lat_iau deg Positional