Mundilfari, or Saturn XXV, is a natural satellite of

Saturn Saturn is the sixth planet from the Sun and the second-largest in the Solar System, after Jupiter. It is a gas giant with an average radius of about nine and a half times that of Earth. It has only one-eighth the average density of Earth; h ...

. It was discovered by

Brett J. Gladman Brett James Gladman (born April 19, 1966) is a Canadian astronomer and a full professor at the University of British Columbia's Department of Physics and Astronomy in Vancouver, British Columbia. He holds the Canada Research Chair in planetary as ...

, et al. in 2000, and given the temporary designation S/2000 S 9. Mundilfari is about 7 kilometres in diameter, and orbits Saturn at an average distance of 18,360 Mm in 928.806 days, at an

inclination Orbital inclination measures the tilt of an object's orbit around a celestial body. It is expressed as the angle between a Plane of reference, reference plane and the orbital plane or Axis of rotation, axis of direction of the orbiting object ...

of 170° to the ecliptic (150° to Saturn's equator), in a retrograde direction and with an eccentricity of 0.198. Mundilfari may have formed from debris knocked off Phoebe by large impacts at some point in the Solar System's history. With a

spectral slope In astrophysics and planetary science, spectral slope, also called spectral gradient, is a measure of dependence of the reflectance on the wavelength. In digital signal processing, it is a measure of how quickly the spectrum of an audio sound tails ...

of −5.0%/100 , Mundilfari is the bluest of all the moons studied by Grav and Bauer (2007), slightly more so than Phoebe (−2.5%/100 nm) and about as blue as

Erriapus Erriapus , or Saturn XXVIII (28), is a prograde irregular satellite of Saturn. It was discovered by Brett Gladman, John J. Kavelaars and colleagues in 2000, and given the temporary designation S/2000 S 10. It was named Erriapo in ...

(+5.1%/100 nm) is red. Its rotation period is hours, the second-fastest among all the irregular moons studied by ''

Cassini–Huygens ''Cassini–Huygens'' ( ), commonly called ''Cassini'', was a space research, space-research mission by NASA, the European Space Agency (ESA), and the Italian Space Agency (ASI) to send a space probe to study the planet Saturn and its system, i ...

'', and it appears to be very elongated in shape. It was named in August 2003 from

Norse mythology Norse, Nordic, or Scandinavian mythology is the body of myths belonging to the North Germanic peoples, stemming from Old Norse religion and continuing after the Christianization of Scandinavia, and into the Nordic folklore of the modern period ...

, where

Mundilfari In Norse mythology Mundilfari (Old Norse: ; rendered variously ''Mundilfari'', ''Mundilföri'' and ''Mundilfœri'') (Old Norse, possibly "the one moving according to particular times"Simek (2007:222).) is the father of Sól, goddess associated ...

is the father of the goddess Sól (Sun) and the god

Mani Mani may refer to: Geography * Maní, Casanare, a town and municipality in Casanare Department, Colombia * Mani, Chad, a town and sub-prefecture in Chad * Mani, Evros, a village in northeastern Greece * Mani, Karnataka, a village in Dakshi ...

(Moon).

References

IAUC 7538: ''S/2000 S 7, S/2000 S 8, S/2000 S 9''
December 7, 2000 (discovery)

December 19, 2000 (discovery and ephemeris)

August 8, 2003 (naming the moon) {{DEFAULTSORT:Mundilfari (Moon) Norse group Moons of Saturn Irregular satellites Discoveries by Brett J. Gladman Astronomical objects discovered in 2000 Moons with a retrograde orbit