Neso
Neso (Natural satellite). See its size, orbit and live position on a 3D map of the Solar System. Neso, also known as Neptune XIII and previously as S/2002 N 4, is the second-outermost-known moon of Neptune, behind S/2021 N 1.
Neso, also known as Neptune XIII and previously as S/2002 N 4, is the second-outermost-known moon of Neptune, behind S/2021 N 1. It was discovered on 14 August 2002 by Matthew Holman, JJ Kavelaars, Tommy Grav, Wesley Fraser, and Dan Milisavljevic at Cerro Tololo Inter-American Observatory, Chile. Named after one of the Nereids from Greek mythology, Neso orbits Neptune at an average distance of 49.9 million km (31.0 million mi)—almost as far as Mercury's orbital distance from the Sun—and takes about 26.8 Earth years to complete one orbit. It is classified as an irregular moon because it follows a distant, highly eccentric, and highly inclined orbit.
- Type: Natural satellite
- Orbiting: Neptune
- Orbital period: 26.8 years