Telesto (moon)

Telesto

Telesto as seen by the Cassini probe on 11 October 2005
Discovery
Discovered by	Bradford A. Smith Harold Reitsema Stephen M. Larson John W. Fountain
Discovery date	April 8, 1980
Designations
Designation	Saturn XIII
Pronunciation	/təˈlɛstoʊ/
Named after	Τελεστώ Telestō
Alternative names	Tethys B S/1980 S 13
Adjectives	Telestoan /tɛləˈstoʊ.ən/ or Telestoian /tɛləˈstoʊ.iən/
Orbital characteristics
Semi-major axis	295000 km
Eccentricity	0.001
Orbital period (sidereal)	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)
Mean diameter	24.6±0.6 km
Volume	7795 km3
Mass	≈ 4×1015 kg (assumed; unmeasured)
Mean density	≈ 0.5 g/cm3 (assumed; unmeasured)
Surface gravity	≈ 0.0011–0.0014 m/s2
Escape velocity	≈ 0.006 km/s at longest axis to ≈ 0.007 km/s at poles
Axial tilt	zero
Apparent magnitude	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' 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.

Exploration

The Cassini probe performed a distant flyby of Telesto on October 11, 2005. The resulting images show that its surface is surprisingly smooth, devoid of small impact craters.

References

Sources

• Hamilton, Calvin J. "Saturn's Trojan Moon Telesto". SolarViews.com. SolarViews. Retrieved 2011-12-23.
• Marsden, Brian G. (April 10, 1980). "Satellites of Saturn" (discovery). IAU Circular. 3466. Retrieved 2011-12-23.
• Marsden, Brian G. (June 6, 1980). "Satellites of Saturn". IAU Circular. 3484. Retrieved 2011-12-23.
• Marsden, Brian G. (April 16, 1981). "Satellites of Saturn". IAU Circular. 3593. Retrieved 2011-12-23.
• Marsden, Brian G. (May 18, 1981). "Satellites of Saturn". IAU Circular. 3605. Retrieved 2011-12-23.
• Marsden, Brian G. (September 30, 1983). "Satellites of Jupiter and Saturn". IAU Circular. 3872. Retrieved 2011-12-23.
• Seidelmann, P. K.; Harrington, R. S.; Pascu, D.; Baum, W. A.; Currie, D. G.; Westphal, J. A.; Danielson, G. E. (1981). "Saturn satellite observations and orbits from the 1980 ring plane crossing". Icarus. 47 (2): 282. Bibcode:1981Icar...47..282S. doi:10.1016/0019-1035(81)90172-X.
• Thomas, P. C. (July 2010). "Sizes, shapes, and derived properties of the saturnian satellites after the Cassini nominal mission" (PDF). Icarus. 208 (1): 395–401. Bibcode:2010Icar..208..395T. doi:10.1016/j.icarus.2010.01.025. Archived from the original (PDF) on 2011-09-27. Retrieved 2015-09-04.
• Thomas, P. C.; Helfenstein, P. (July 2020). "The small inner satellites of Saturn: Shapes, structures and some implications". Icarus. 344: 20. Bibcode:2020Icar..34413355T. doi:10.1016/j.icarus.2019.06.016. S2CID 197474587. 113355.

External links

• NASA - Telesto Profile
  • NASA's Solar System Exploration
• The Planetary Society: Telesto