What is Nereid (moon)?
{{Infobox Planet | bgcolour = #a0ffa0 | name = Nereid | image = Nereid-Voyager2.jpg | discoverer = [[Gerard P. Kuiper]] | discovered = May 1, 1949 | semimajor = 5,513,400 [[kilometre|km]] (0.03685 [[Astronomical unit|AU]]) | eccentricity = 0.7512 | periapsis = 1,353,600 [[kilometer|km]] (0.00905 [[Astronomical unit|AU]]) | apoapsis = 9,623,700 [[kilometer|km]] (0.06433 [[Astronomical unit|AU]]) | period = 360.1362 [[days|d]] | avg_speed = 1.12 km/s | inclination = 5.07° (to [[Ecliptic]]) <br /> 32.55° (to Neptune's equator) <br /> 7.232° (to the local [[Laplace plane]]) | satellite_of = [[Neptune (planet)|Neptune]] | mean_radius = 170 km | mass = 3.1{{e|19}} [[kilogram|kg]] | density = 1.5 g/cm<sup>3</sup> | rotation = 0.48 d (11 h 31 min) | albedo = 0.14 | single_temperature = ~51 [[Kelvin|K]] mean (estimate) }} '''Nereid''' or '''Neptune&nbsp;II''', is a [[Satellite (natural)|moon]] of [[Neptune (planet)|Neptune]]. Nereid was found on 1 May 1949 by [[Gerard Kuiper]], who suggested the name in the report of his discovery. It is named after the [[Nereids]], sea-nymphs of [[Greek mythology]]. It was the farthest of Neptune's known moons for a long time ([[Halimede (moon)|Halimede]] through [[Neso (moon)|Neso]] have since taken that honour), and is the third biggest, with a diameter of 340&nbsp;km. Its [[orbit]] averages 5,513,400&nbsp;km in radius, but is very [[Orbital eccentricity|eccentric]] and varies from 1,353,600 to 9,623,700 kilometres. For a long time this was the most highly eccentric orbit of any known moon in the [[solar system]], but [[Bestla (moon)|Bestla]], a more recently discovered moon of [[Saturn (planet)|Saturn]] has a more eccentric orbit. The unusual orbit suggests that it may be a captured [[asteroid]] or [[Kuiper belt]] object, or possibly that it was perturbed during the capture of Neptune's largest moon [[Triton (moon)|Triton]]. Very little else is known of Nereid. Nereid was too far to be properly imaged by the ''[[Voyager 2]]'' [[space probe|probe]] when it visited the Neptun