Gridr
A confirmed moon in the Saturn system.
Physical measurements
- Mean radius
- — No value in the admitted source set.
- GM · gravitational parameter
- — No value in the admitted source set.
- Mass
- — Mass requires an admitted GM estimate.
- Mean density
- — No value in the admitted source set.
Orbit descriptions
Mean elements describe an average orbit. They are not positions for a chosen date.
SAT456 · ecliptic plane · 2000-01-01.5 TDB
- Semimajor axis
- 19,250,600 km
- Sidereal period
- 997.332 days
- Eccentricity
- 0.187
- Inclination to reference plane
- 163.9°
- Argument of periapsis
- 271.4°
- Mean anomaly
- 197°
- Ascending node
- 330.8°
- Apsidal / nodal precession periods
- 225.9 / 407.9 years
- Reference-plane pole RA / Dec
- — / —°
- Plane tilt to parent equator
- —°
- Reference center
- Not specified in this summary sourceThe summary table identifies a parent system but does not explicitly specify the reference center for each solution. Do not infer a physical-primary center, especially for Pluto’s circumbinary moons.
Orientation
No supported orientation model in the admitted PCK source.
Identity & availability
- Stable catalog ID
- gridr
- JPL / NAIF satellite ID
- 654
- Names & designations
- Gridr · S/2004 S 20
- Discovery / rediscovery years
- 2004S.S. Sheppard, D.C. Jewitt, J. Kleyna
No validated dated trajectory admitted in catalog 1.0.0. Mean elements are not ephemerides.
No image or global texture admitted in this catalog release.No environment measurements admitted in this catalog release.
Sources & evidence
- JPL discovery circumstancestable tr[174] (zero-based); saturn / Gridr · References: MPEC 2019-T126
- MPC planetary satellite listitems[97]; Saturn 54
- MPC satellite namesitems[61]; Saturn 54
- JPL mean orbital elements#sat_elem row ID=171; Saturn / Gridr / NAIF 654 · References: 48
Full catalog, uncertainty and source manifests · All Saturn moons · Moon model limits