Neptune · natural satellite

Larissa

Mean diameter: 192 km
Mean orbital distance: 73,600 km from centre
Orbital period: 0.555 Earth days

Compared with our Moon

Larissa · 192 km

Moon · 3,474.8 km

One diameter scale. Circle shapes compare volume-equivalent diameters; irregular moons are not spheres.

Orbit & discovery

Surface gravity: 0.028 m/s²
Discovery: 1989
Discoverer / team: Voyager Science Team
Provisional designation: S/1989 N2
JPL satellite ID: 807
Orbital eccentricity: 0.001
Inclination: 0.2 degrees

Inclination reference: equatorial. Mean-element epoch: 2000-01-01.5 TDB · NEP098.

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.

Physical measurements & uncertainties

Mean radius · km: 96.00 ±7.00 [1]
GM · km³/s²: 0.25484 ±3.12230 [NEP097]
Density · g/cm³: 1.0303 ±12.626 [*]

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