Skathi (moon)

Skathi
Discovery images of Skathi (circled) taken by the Canada–France–Hawaii Telescope in September 2000
Discovery
Discovered byBrett J. Gladman
John J. Kavelaars et al.[a]
Discovery siteMauna Kea Observatory
Discovery dateSeptember 23, 2000
Designations
Designation
Saturn XXVII
Named after
Skaði
S/2000 S 8
Orbital characteristics[3][4]
15541000 km
Eccentricity0.270
−728.2 days
Inclination152.6°
Satellite ofSaturn
GroupNorse group
Physical characteristics[5][4]
8+50%
−30% km
11.10±0.02 h
Albedo0.06 (assumed)
23.6
14.3

Skathi /ˈskɑːði/,[6][b] also named Saturn XXVII and originally spelled Skadi, is a natural satellite of the planet Saturn. Skathi is one of Saturn's irregular moons, in its Norse group of satellites. It was discovered on September 23, 2000, by a team of astronomers led by Brett Gladman. The team announced their discovery on December 7, 2000,[7] along with seven other satellites of Saturn, namely; Tarvos, Ijiraq, Thrymr, Siarnaq, Mundilfari, Erriapus, and Suttungr.[8] The moon was named after Skaði, a figure in Norse mythology, as part of an effort to diversify the largely Greek and Roman names of astronomical objects.

Skathi takes just over 725 days to complete an orbit of Saturn and it is estimated to take 11.10±0.02 hours to rotate on its axis. It orbits at a greater distance from Saturn than many of the planet's other satellites, with a large orbital inclination and eccentricity, and it moves in a retrograde direction. Not much is known about Skathi, because it is a dim object. Other than Earth-based observations, it has only been observed by the Cassini probe, and even those measurements were taken at a distance of nearly 9.7 million kilometres (6 million miles).

Skathi's origin remains an open question. One possibility is that it was originally an asteroid that formed elsewhere, and was captured by Saturn's gravity as it flew by the planet. Another possibility is that it was originally a portion of one of Saturn's moons, like Phoebe, that split off during a collision and became an independent satellite. Its physical composition has not been determined, but it is known to be about 8 kilometres (5 mi) across, and to have an irregular shape.

  1. ^ "Planetary Satellite Discovery Circumstances". NASA. 28 October 2019. Retrieved 27 July 2020.
  2. ^ Cite error: The named reference nasa was invoked but never defined (see the help page).
  3. ^ Sheppard, Scott S. (2019). "Moons of Saturn". Carnegie Science. Retrieved 4 April 2021.
  4. ^ a b Cite error: The named reference denk18 was invoked but never defined (see the help page).
  5. ^ Denk, T.; Mottola, S. (2019). Cassini Observations of Saturn's Irregular Moons (PDF). 50th Lunar and Planetary Science Conference. Lunar and Planetary Institute.
  6. ^ Kuiper, Kathleen, ed. (1995). Merriam-Webster's Encyclopedia of Literature. Springfield, Massachusetts: Merriam-Webster. p. 1038. ISBN 978-08777-9-042-6.
  7. ^ Cite error: The named reference IAUC was invoked but never defined (see the help page).
  8. ^ Blunck, Jürgen (2009). Solar System Moons: Discovery and Mythology. Berlin: Springer Science & Business Media. p. 59. ISBN 978-3-540-68853-2.


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