Goddard Space Center
The researchers of the organization, Martha and Bradley Schaeffer, in the issue of the journal NATURE of last June 2, have stated that Nereida is not spherical and has an irregular appearance.
According to photometric measurements made in 1987, the color spectrum of the satellite does not resemble that of other satellites and asteroids. In his section of study the brightness of Nereida varied in a ratio of four to one. The way to explain it is to consider the satellite as non-spherical.
However, this does not correspond to theoretical forecasts. Any object of 400 km of diameter by gravity must have a spherical shape (Nereida has a diameter of 660 km).