Nereid

Neptune II

Nereid ( "NEER ee ed" ) is the outermost of Neptune's known satellites and the third largest:

        orbit:    5,513,400 km distance from Neptune
        diameter: 340 km
        mass:     ?

Discovered in 1949 by Kuiper.

Nereid's orbit is the most highly eccentric of any planet or satellite in the solar system; its distance from Neptune varies from 1,353,600 to 9,623,700 kilometers.

Nereid's odd orbit indicates that it may be a captured asteroid or Kuiper Belt object.

Open Issues

• We know next to nothing about Nereid.
• How did it come to be in such an odd orbit?