Neptune · natural satellite

Neso

Mean diameter: Not available
Mean orbital distance: 49,897,800 km from centre
Orbital period: 9,805 Earth days

Orbit & discovery

Surface gravity: Not available
Discovery: 2002
Discoverer / team: M. Holman, J. Kavelaars, T. Grav, W. Fraser, D. Milisavljevic
Provisional designation: S/2002 N4
JPL satellite ID: 813
Orbital eccentricity: 0.455
Inclination: 128.4 degrees

Inclination reference: ecliptic. Mean-element epoch: 2020-01-01.0 TDB · NEP104.

Diameters use volume-equivalent mean radii, including for irregular bodies. Mean orbital elements describe an orbit; they are not live positions. Missing physical measurements remain unavailable.

Missions in the Neptune system · 1 records

1 launches · 0 linked events

These records cover the planetary system. A system mission did not necessarily visit this moon. Dedicated targets are marked separately; programme events include the journey and briefings. Launch outcomes do not establish arrival, landing success or present spacecraft operation.

Dedicated targets only

PLANETARY SYSTEM

Voyager 2

August 20, 1977 · UTC

Lockheed Martin · Titan IIIE

1 records from the complete 9,386‑record production catalogue.

Sources & measurements