Helene (moon)
From Academic Kids
| |
| Discovery | |
|---|---|
| Discovered by | Laques and Lecacheux |
| Discovered in | March 1, 1980 |
| Orbital characteristics | |
| Semimajor axis | 377,396 km |
| Eccentricity | 0.0022 |
| Orbital period | 2.736915 d [1] (http://exp.arc.nasa.gov/downloads/celestia/data/solarsys.ssc) |
| Inclination | 0.199° (to Saturn's equator) |
| Satellite of | Saturn |
| Physical characteristics | |
| Mean diameter | 32 km (36 × 32 × 30) |
| Mass | ?kg |
| Mean density | ? g/cm3 |
| Surface gravity | ?m/s2 |
| Escape velocity | ?km/s |
| Rotation period | assumed synchronous |
| Axial tilt | zero |
| Albedo | ? |
| Surface temperature | ? K |
| Atmosphere | none |
Helene (hel'-e-nee, Greek ‘Ελένη) is a moon of Saturn. It was discovered by Pierre Laques and Jean Lecacheux in 1980 from ground-based observations at Pic du Midi Observatory, and was designated S/1980 S 6. In 1988 it was officially named after Helene of Greek mythology. It is also designated as Saturn XII.
It is co-orbital with Dione and located in its leading Lagrangian point (L4) and hence, before it received its permanent name of "Helene" it was usually referred to as "Dione B".
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External links
- The Planetary Society: Helene (http://www.planetary.org/saturn/helene.html)
| Saturn's natural satellites |
|---|
| Janus' group | Mimas | Enceladus | Tethys | Dione | Rhea | Titan | Hyperion | Iapetus | Inuit group | Gallic group | Norse group |
fr:Hélène (lune) nl:Helene (maan) nn:Saturnmånen Helene zh:土卫十二
