2.3.1 spase://CNES/NumericalData/CDPP-AMDA/Ephemerides/dione-orb-all Dione 2017-10-14T11:46:29Z Dione orbits Saturn with a semimajor axis about 2% less than that of the Moon. However, reflecting Saturn's greater mass (95 times that of Earth's), Dione's orbital period is one tenth that of the Moon. Dione is currently in a 1:2 mean-motion orbital resonance with moon Enceladus, completing one orbit of Saturn for every two orbits completed by Enceladus. This resonance maintains Enceladus's orbital eccentricity (0.0047), providing a source of heat for Enceladus's extensive geological activity, which shows up most dramatically in its cryovolcanic geyser-like jets. The resonance also maintains a smaller eccentricity in Dione's orbit (0.0022), tidally heating it as well. Dione has two co-orbital, or trojan, moons, Helene and Polydeuces. They are located within Dione's Lagrangian points L4 and L5, 60 degrees ahead of and behind Dione respectively. spase://CNES/Person/NAIF PrincipalInvestigator sat-moons-orb PartOf Saturn Moons spase://SMWG/Repository/CNES/CDPP-AMDA Online Open http://amda.cdpp.eu Text.ASCII SPICE spase://CNES/Instrument/CDPP-AMDA/Ephemerides Ephemeris 1970-01-01T00:00:00Z 2022-12-23T23:19:59Z PT20M Saturn Saturn.Dione distance dione-saturn dio_sat_r Rs TimeSeries Positional xyz_ksm dio_sat_ksm Rs Cartesian KSM TimeSeries 3 x 1 dio_sat_ksm(0) y 2 dio_sat_ksm(1) z 3 dio_sat_ksm(2) Positional xyz_kso dio_sat_kso Rs Cartesian KSO TimeSeries 3 x 1 dio_sat_kso(0) y 2 dio_sat_kso(1) z 3 dio_sat_kso(2) Positional xyz_IAU_saturn dio_sat_xyz Rs Cartesian IAU_Saturn TimeSeries 3 x 1 dio_sat_xyz(0) y 2 dio_sat_xyz(1) z 3 dio_sat_xyz(2) Positional latitude IAU_saturn dio_sat_lat deg Positional longitude IAU_saturn dio_sat_lon deg Positional