Tethys is a natural satellite of Saturn in the NASA/JPL Solar System Dynamics planetary satellite tables.
- Planet: Saturn
- Satellite: Tethys
- Satellite code: 603
- GM: 41.21353 ± 0.00031 km³/s² (ephemeris SAT441)
- Mean Radius: 531.10 ± 0.60 km (reference 1)
- Mean Density: 0.9840 ± 0.0033 g/cm³ (NASA note: Mean Density is derived from the specified GM and Mean Radius.)
- Ephemeris: SAT441
- Reference frame: Laplace
- Epoch (TDB): 2000-01-01.5
- Semi-major axis a: 295000. km
- Eccentricity e: 0.001
- Argument of periapsis ω: 335.3 deg
- Mean anomaly M: 0.0 deg
- Inclination i: 1.1 deg
- Longitude of ascending node: 273.0 deg
- Sidereal period P: 1.887802 days
- Argument of periapsis precession period: 0.005 yr
- Longitude of ascending node precession period: 4.982 yr
- Laplace-plane pole right ascension: 40.6 deg
- Laplace-plane pole declination: 83.5 deg
- Laplace-plane tilt: 0.0 deg
- Mean elements reference: 36