Pandora

Pandora

Pandora, as imaged by Cassini
Discovery
Discovered by	Collins, Voyager 1
Discovery date	October, 1980
Orbital characteristics [1]
Epoch December 31, 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
Proper orbital elements
Physical characteristics
Dimensions	104×81×64 km [2]
Mean radius	40.7 ± 1.5 km [2]
Volume	~280,000 km³
Mass	1.371 ± 0.019 ×1017 kg [2]
Mean density	0.49 ± 0.06 g/cm³ [2]
Equatorial surface gravity	0.0026–0.0060 m/s² [2]
Escape velocity	~0.019 km/s
Rotation period	synchronous
Axial tilt	zero
Albedo	0.6
Temperature	~78 K

Pandora ( /pænˈdɔərə/ pan-DOHR-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 kilometres (19 mi) in diameter.^[6]

The orbit of Pandora appears to be chaotic, as a consequence of a series of four 118:121 mean motion resonances with Prometheus.^[7] 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 kilometres (870 mi). 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.

Gallery

• 

  Voyager 2 image of Pandora (August 1981).

• 

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

• 

  Cassini captured this close view of Saturn's moon Pandora during the spacecraft's flyby on June 3, 2010.

References

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Citations

Sources

• Marsden, Brian G. (October 31, 1980). "Satellites of Saturn" (discovery). IAU Circular 3532. http://www.cbat.eps.harvard.edu/iauc/03500/03532.html. Retrieved 2011-12-29. 
• Marsden, Brian G. (January 3, 1986). "Satellites of Saturn and Pluto" (naming the moon). IAU Circular 4157. http://www.cbat.eps.harvard.edu/iauc/04100/04157.html. Retrieved 2011-12-29. 
• Renner, Stéfan F.; Sicardy, Bruno; French, Richard G. (March 2005). "Prometheus and Pandora: Masses and orbital positions during the Cassini tour". Icarus 174 (1): 230–240. Bibcode 2005Icar..174..230R. doi:10.1016/j.icarus.2004.09.005.  edit
• "Saturn: Moons: Pandora". Solar System Exploration: Planets. NASA. 4 Apr 2011. http://solarsystem.nasa.gov/planets/profile.cfm?Object=Sat_Pandora. Retrieved 2011-12-29. 
• Spitale, J. N.; Jacobson, R. A.; Porco, C. C.; Owen, W. M., Jr. (2006). "The orbits of Saturn's small satellites derived from combined historic and Cassini imaging observations". The Astronomical Journal 132 (2): 692–710. Bibcode 2006AJ....132..692S. doi:10.1086/505206.  edit
• Thomas, P. C. (July 2010). "Sizes, shapes, and derived properties of the saturnian satellites after the Cassini nominal mission". Icarus 208 (1): 395–401. Bibcode 2010Icar..208..395T. doi:10.1016/j.icarus.2010.01.025. http://www.ciclops.org/media/sp/2011/6794_16344_0.pdf.  edit
• USGS/IAU (July 21, 2006). "Planet and Satellite Names and Discoverers". Gazetteer of Planetary Nomenclature. USGS Astrogeology. http://planetarynames.wr.usgs.gov/Page/Planets#SaturnianSystem. Retrieved 2011-12-29. 

External links

Wikimedia Commons has media related to: Pandora (moon)

• Pandora at NASA's Solar System Exploration
• Pandora at The Planetary Society