|Discovered||August 14, 2002|
|Mean orbital elements |
|Epoch June 10, 2003|
|Semi-major axis||22.228 Gm|
|Orbital period||2912.72 days
|Mean diameter||44 km **|
*to the ecliptic**based on the albedo
Sao follows an exceptionally inclined and moderately eccentric orbit illustrated on the diagram in relation to other irregular satellites of Neptune. The satellites above the horizontal axis are prograde, the satellites beneath it are retrograde. The yellow segments extend from the pericentre to the apocentre, showing the eccentricity.
Sao, or Neptune XI, like many of the outer satellites of Neptune, is named after one of the Nereids; Sao was associated with sailing and is referred to as "The rescuer" or "Safety". Before the announcement of its name on February 3, 2007 (IAUC 8802), Sao was known provisionally as S/2002 N 2.
- JPL (2011-07-21). "Planetary Satellite Discovery Circumstances". Jet Propulsion Laboratory. Retrieved 2011-10-24.
- Green, Daniel W. E. (January 13, 2003). "Satellites of Neptune". IAU Circular. 8047. Retrieved 2011-10-24.
- Jacobson, R. A. (2008). "NEP078 – JPL satellite ephemeris". Planetary Satellite Mean Orbital Parameters. Retrieved 2009-09-23.
- Sheppard, Scott S.; Jewitt, David C.; Kleyna, Jan (2006). "A Survey for "Normal" Irregular Satellites around Neptune: Limits to Completeness". The Astronomical Journal. 132: 171–176. arXiv:. Bibcode:2006AJ....132..171S. doi:10.1086/504799.
- Holman, M. J.; Kavelaars, J. J.; Grav, T.; et al. (2004). "Discovery of five irregular moons of Neptune" (PDF). Nature. 430 (7002): 865–867. Bibcode:2004Natur.430..865H. doi:10.1038/nature02832. PMID 15318214. Retrieved 24 October 2011.