Pandora (moon)

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Pandora
Pandora PIA07632.jpg
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 141720±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 104 × 81 × 64 km [2]
Mean radius 40.7±1.5 km [2]
Volume ≈ 280000 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; 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. Majority of craters on Pandora are shallow as a result of being filled with debris. Ridges and grooves are also present on moon's surface.[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[edit]

References[edit]

Citations

Sources

External links[edit]

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