Pandora (moon)

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There is also an asteroid called 55 Pandora.
Pandora
Pandora, as imaged by Cassini
Discovery
Discovered by Collins, Voyager 1
Discovery date October, 1980
Epoch 31 December 2003 (JD 2453005.5
Semi-major axis 141,720 ± 10 km
Eccentricity 0.0042
Orbital period 0.628504213 d
Inclination 0.050 ± 0.004° to Saturn's equator
Satellite of Saturn
Physical characteristics
Dimensions 103×80×64 km[2]
Mean radius 40.3 ± 2.2 km[2]
Surface area ~21,000 km²
Volume ~270,000 km³
Mass 1.356 ± 0.022 ×1017 kg[1]
Mean density 0.49 ± 0.08 g/cm³
Equatorial surface gravity 0.0034 m/s2
Escape velocity ~0.019 km/s
Rotation period synchronous
Axial tilt zero
Albedo 0.6
Temperature ~78 K

Pandora (pronounced /pænˈdɔərə/ pan-DOR-ə, Greek Πανδώρα) is an inner satellite of Saturn. It was discovered in 1980 from photos taken by the Voyager 1 probe, and was provisionally designated S/1980 S 26.[3] In late 1985 it was officially named after Pandora from Greek mythology.[4] It is also designated as Saturn XVII.[5]

Pandora is the outer shepherd satellite of the F Ring. It is more heavily cratered than nearby Prometheus, and has at least two large craters 30 km in diameter.[6]

The orbit of Pandora appears to be chaotic, as a consequence of a mean motion resonance with Prometheus. The most appreciable changes in their orbits occur approximately every 6.2 years,[1] when the periapsis of Pandora lines up with the apoapsis of Prometheus and the moons approach to within about 1,400 km. Pandora also has a 3:2 mean-motion resonance with Mimas.[1]

From its very low density and relatively high albedo, it seems likely that Pandora is a very porous icy body. There is a lot of uncertainty in these values, however, so this remains to be confirmed.

[edit] Gallery

Voyager 2 image of Pandora.

Pandora as seen from the Cassini probe in 2005; the rings of Saturn are in the background.

[edit] References

  1. ^ a b c d 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. ^ a b Porco, C. C.; et al. (2006). "Physical Characteristics and Possible Accretionary Origins for Saturn's Small Satellites". Bulletin of the American Astronomical Society 37: 768. 
  3. ^ IAUC 3532: Satellites of Saturn 1980 October 31 (discovery)
  4. ^ IAUC 4157: Satellites of Saturn and Pluto 1986 January 3 (naming the moon)
  5. ^ Planet and Satellite Names and Discoverers. Gazetteer of Planetary Nomenclature. USGS Astrogeology (July 21, 2006). Retrieved on 2006-08-07.
  6. ^ NASA JPL Solar System Exploration: Saturn: Moons: Pandora

[edit] External links


v • d • e
Moons of Saturn
Generally listed in increasing distance from Saturn. Temporary names in italics.
Ring shepherds
moonlets · Pan · Daphnis · Atlas · Prometheus ·  ?S/2004 S 6 · ?S/2004 S 4 · ?S/2004 S 3 · Pandora
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