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:     ?

Nereid is any one of the sea nymphs, the 50 daughters of Nereus and Doris.

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?