Methone (moon)

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Methone is seen in part of a sequence
taken to search for new moons on June 1, 2004
Discovery
Discovered by Cassini Imaging Science Team
Discovered on 1 June 2004
Orbital characteristics[1]
Epoch 20 June 2004 (JD 2453177.5)
Semimajor axis 194,440 ± 20 km
Eccentricity 0.0001
Orbital period 1.009573975 d
Inclination
(to Saturn's equator)		 0.007 ± 0.003°
Is a satellite of Saturn
Physical characteristics
Mean diameter ≈ 3 km
Mass 0.7 − 3 ×1013 kg [2]
Mean density unknown
Surface gravity unknown
Rotation period synchronous
Axial tilt unknown
Albedo unknown
Atmosphere none

Methone (pronounced /mɨˈθoʊni/ mi-THOE-nee, or as Greek Μεθωνη) is a very small natural satellite of Saturn lying between the orbits of Mimas and Enceladus.

It was first seen by the Cassini Imaging Team[3][4] and given the temporary designation S/2004 S 1. Methone is also named Saturn XXXII.

Methone is visibly affected by a perturbing mean longitude resonance with the much larger Mimas. This causes its osculating orbital elements to vary with an amplitude of about 20 km in semi-major axis, and 5° in longitude on a timescale of about 450 days. Eccentricity also varies on different timescales between 0.0011 and 0.0037, and inclination between about 0.003° and 0.020°.[1]

The name Methone was approved by the IAU Working Group on Planetary System Nomenclature on January 21, 2005.[5] It was ratified at the IAU General Assembly in 2006. Methone was one of the Alkyonides, the seven beautiful daughters of the Giant Alkyoneus.[6]

[edit] References

  1. ^ a b Spitale, J. N.; et al. (2006). "The orbits of Saturn's small satellites derived from combined historic and Cassini imaging observations". The Astronomical Journal 132: 692. doi:10.1086/505206. 
  2. ^ based on density 0.5 - 2 g/cm³
  3. ^ * C.C. Porco, et al., IAUC 8389: S/2004 S 1 and S/2004 S 2 2004 August 16 (discovery)
  4. ^ Porco, C. C.; et al.; (2005); Cassini Imaging Science: Initial Results on Saturn's Rings and Small Satellites, Science, Vol. 307, No. 5713, pp. 1226-1236
  5. ^ IAUC 8471: Satellites of Saturn 2005 January 21 (naming the moon)
  6. ^ Early press releases of the discovery mentioned the first person to see the moon in Cassini images. This bit of trivia was blown out of proportion in the following months, with this individual being credited as the "discoverer" by some sources. Because the discovery was a large team effort, involving tens of people and hundreds of hours of distributed work, a conscious decision was made by the IAU to officially and correctly assign any credit to "the Cassini Imaging team" and to avoid unfairly singling out any one individual as the discoverer.

[edit] External links

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v • d • e
Moons of Saturn
Generally listed in increasing distance from Saturn. Temporary names in italics.
Ring shepherds
Co-orbitals
Inner large (and Trojan)
Mimas · Methone · Anthe · Pallene · Enceladus · Tethys (Telesto • Calypso) · Dione (Helene • Polydeuces)
Outer large
Inuit group
Norse group
Gallic group
Rings of Saturn · Cassini-Huygens · Themis · Chiron