Telesto (moon)
Telesto as seen by the Cassini probe on 11 October 2005 | |
| Discovery | |
|---|---|
| Discovered by |
|
| Discovery date | April 8, 1980 |
| Designations | |
Designation | Saturn XIII |
| Pronunciation | /təˈlɛstoʊ/ |
Named after | Τελεστώ Telestō |
| Tethys B S/1980 S 13 | |
| Adjectives | Telestoan /tɛləˈstoʊ.ən/ or Telestoian /tɛləˈstoʊ.iən/ |
| Orbital characteristics | |
| 295000 km | |
| Eccentricity | 0.001 |
| 1.887802 d | |
| Inclination | 1.19° (to Saturn's equator) |
| Satellite of | Saturn |
| Group | L4 Tethys trojan |
| Physical characteristics | |
| Dimensions | 33.2 × 23.4 × 19.2 km (± 0.6 × 0.6 × 0.4 km): 2 |
| 24.6±0.6 km: 2 | |
| Volume | 7795 km3 |
| Mass | ≈ 4×1015 kg (assumed; unmeasured) |
Mean density | ≈ 0.5 g/cm3 (assumed; unmeasured): 3 |
| ≈ 0.0011–0.0014 m/s2: 3 | |
| ≈ 0.006 km/s at longest axis to ≈ 0.007 km/s at poles | |
| zero | |
| 18.7 | |
Telesto /təˈlɛstoʊ/ is a moon of Saturn. It was discovered by Smith, Reitsema, Larson and Fountain in 1980 from ground-based observations, and was provisionally designated S/1980 S 13. In the following months, several other apparitions were observed: S/1980 S 24, S/1980 S 33, and S/1981 S 1.
In 1983 it was officially named after Telesto of Greek mythology. It is also designated as Saturn XIII or Tethys B.
Telesto is co-orbital with Tethys, residing in Tethys's leading Lagrangian point (L4). This relationship was first identified by Seidelmann et al. in 1981. Another moon, Calypso, resides in the other (trailing) Lagrangian point of Tethys, 60 degrees in the other direction from Tethys. The Saturnian system has two additional trojan moons. It eclipsed Tethys in 2024.