S/2021 J 8

A confirmed moon in the Jupiter system.

Unnamed · S/2021 J 8

Snapshot 2026-09-09 · catalog 1.0.0

Explore S/2021 J 8 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.

JUP349 · ecliptic plane · 2000-01-01.5 TDB
Semimajor axis
20,978,900 km
Sidereal period
620.849 days
Eccentricity
0.243
Inclination to reference plane
147.1°
Argument of periapsis
34.6°
Mean anomaly
85°
Ascending node
132°
Apsidal / nodal precession periods
86.5 / 122.4 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
s-2021-j-8
JPL / NAIF satellite ID
55544
Names & designations
S/2021 J 8
Discovery / rediscovery years
2021S.S. Sheppard, D.J. Tholen, C. Trujillo

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[115] (zero-based); jupiter / S/2021 J 8 · References: MPEC 2026-G73
  2. MPC planetary satellite listitems[324]; S/2021 J 8
  3. JPL mean orbital elements#sat_elem row ID=117; Jupiter / S2021_J_8 / NAIF 55544 · References: 52

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