Fenrir

A confirmed moon in the Saturn system.

Named · Saturn XLI · S/2004 S 16

Snapshot 2026-09-09 · catalog 1.0.0

Explore Fenrir in Orrery

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
22,330,800 km
Sidereal period
1,245.92 days
Eccentricity
0.137
Inclination to reference plane
164.5°
Argument of periapsis
114.5°
Mean anomaly
38.6°
Ascending node
234.6°
Apsidal / nodal precession periods
189.4 / 350.1 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
fenrir
JPL / NAIF satellite ID
641
Names & designations
Fenrir · S/2004 S 16
Discovery / rediscovery years
2004S. 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

  1. JPL discovery circumstancestable tr[161] (zero-based); saturn / Fenrir · References: IAUC 8523
  2. MPC planetary satellite listitems[93]; Saturn 41
  3. MPC satellite namesitems[52]; Saturn 41
  4. JPL mean orbital elements#sat_elem row ID=160; Saturn / Fenrir / NAIF 641 · References: 48

Full catalog, uncertainty and source manifests · All Saturn moons · Moon model limits