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Solar System Exploration
Planets
Neso: Overview
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Chart showing Neptune's moons, including Neso.
The discovery image of Neso is currently unavailable.

Very little is known about Neso, another of Neptune's extremely distant irregular moons. Neso's eccentric orbit takes it millions of kilometers from the ice giant. The moon's orbit is among the most distant from its planet than any other known moon in our solar system.

The small moon shares similar orbital parameters with another moon of Neptune -- Psamathe. Both Neso and Psamathe may be fragments from the break-up of a larger moon billions of years ago.

Discovery:
Neso was discovered in 2002 by Matthew J. Holman, John J. Kavelaars, Tommy Grav, Wesley C. Fraser, and Dan Milisavljevic using the 4-m Blanco telescope at Cerro Tololo Observatory in Chile.

How Neso Got its Name:
Moons of Neptune are named for characters from Greek or Roman mythology associated with Neptune or Poseidon, or the oceans. Irregular satellites are named for the Nereids, daughters of Nereus and Doris and the attendants of Neptune.

Neso like many of the outer satellites of Neptune, is named after one of the Nereids. Neso was originally designated S/2002 N 4.

Just the Facts
Orbit Size (semi-major axis):  49,285,000 km
Mean Radius:  30.0 (assuming an albedo of 0.04) km
Volume:  113,097 km3
Mass:  164,853,527,640,691,000 kg
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Last Updated: 6 Feb 2014