Ersa

A confirmed moon in the Jupiter system.

Named · Jupiter LXXI · S/2018 J 1

Snapshot 2026-09-09 · catalog 1.0.0

Explore Ersa 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.

JUP347 · ecliptic plane · 2000-01-01.5 TDB
Semimajor axis
11,399,400 km
Sidereal period
248.615 days
Eccentricity
0.117
Inclination to reference plane
29°
Argument of periapsis
300.7°
Mean anomaly
270.8°
Ascending node
113.7°
Apsidal / nodal precession periods
192.6 / 306.2 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
ersa
JPL / NAIF satellite ID
571
Names & designations
Ersa · S/2018 J 1
Discovery / rediscovery years
2018S.S. Sheppard

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[75] (zero-based); jupiter / Ersa · References: MPEC 2018-O18
  2. MPC planetary satellite listitems[219]; Jupiter 71
  3. MPC satellite namesitems[44]; Jupiter 71
  4. JPL mean orbital elements#sat_elem row ID=73; Jupiter / Ersa / NAIF 571 · References: 47

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