This fuzzy Voyager 2 image taken in 1989 helped scientists determine Nereid's size.

Nereid is one of the outermost of Neptune's known moons and is among the largest. Nereid is unique because it has one of the most eccentric orbits of any moon in our solar system. Nereid is so far from Neptune that it requires 360 Earth days to make one orbit. This odd orbit suggests that Nereid may be a captured asteroid or Kuiper Belt object or that it was greatly disturbed during the capture of Neptune's largest moon Triton.

Discovery
Nereid was discovered on 1 May 1949 by Gerard P. Kuiper with a ground-based telescope. It was the last satellite of Neptune to be discovered before Voyager 2's discoveries four decades later.

How Nereid 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.

Nereid (NEER-ee-ed) is named after the Nereids, sea-nymphs of Greek mythology. Kuiper proposed the name when he reported his discovery.