Pandora (moon)
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- There is also an asteroid called 55 Pandora.
 Pandora, as imaged by Cassini |
|
| Discovery | |
|---|---|
| Discovered by: | Collins, Voyager 1 |
| Discovery date: | October, 1980 |
| Orbital characteristics [1] | |
| 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 (pan-dor'-a, IPA: [pænˈdo.ɹə], 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 1985 it was officially named after Pandora from Greek mythology. It is also designated as Saturn XVII.[4]
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 [1].
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 1400 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] References
- ^ a b c d J.N. Spitale et al (2006). "The orbits of Saturn's small satellites derived from combined historic and Cassini imaging observations". The Astronomical Journal 132: 692.
- ^ a b C.C. Porco et al. (2006). "Physical characteristics and possible accretionary origins for Saturn's small satellites". Bulletin of the American Astronomical Society 37: 768.
- ^ Smith, B. A. (October 31, 1980). IAU Circular No. 3532. Retrieved on 2006-08-07.
- ^ Planet and Satellite Names and Discoverers. Gazetteer of Planetary Nomenclature. USGS Astrogeology (July 21, 2006). Retrieved on 2006-08-07.
[edit] External links
| Moons of Saturn | |
|---|---|
|
Generally listed in increasing distance from Saturn
|
|
| Ring shepherds | Pan · Daphnis · Atlas · Prometheus · S/2004 S 6 · S/2004 S 4 · S/2004 S 3 · Pandora |
| Co-orbitals | Epimetheus · Janus |
| Inner large and Trojan | Mimas · Methone · Pallene · Enceladus · Tethys (trojans Telesto, Calypso) · Dione (trojans Helene, Polydeuces) |
| Outer large | Rhea · Titan · Hyperion · Iapetus |
| Inuit group | Kiviuq · Ijiraq · Paaliaq · S/2004 S 11 · Siarnaq |
| Norse group | Phoebe · Skathi · S/2006 S 8 · S/2004 S 13 · S/2006 S 4 · S/2004 S 19 · Mundilfari · S/2006 S 6 · S/2006 S 1 · S/2004 S 17 · Narvi · S/2004 S 15 · S/2004 S 10 · Suttungr · S/2004 S 12 · S/2004 S 18 · S/2004 S 9 · S/2004 S 14 · S/2004 S 7 · Thrymr · S/2006 S 3 · S/2006 S 7 · S/2006 S 2 · S/2004 S 16 · Ymir · S/2006 S 5 · S/2004 S 8 |
| Gallic group | Albiorix · Erriapo · Tarvos |
