Space · Moons
Telesto
A moon of Saturn — A Trojan moon of Tethys — leads Tethys at the L4 Lagrange point.
Quick facts
Parent planet
Diameter (mean)
24 km
Mass
9.4 × 10¹⁵ kg
1.3e-07 Moon masses
Mean orbital radius
294,710 km
Orbital period
1.888 Earth days
Discovery year
1980
Discoverer
Bradford A. Smith et al.
Naming origin
Oceanid nymph, daughter of Tethys
Surface conditions
Telesto is the leading Trojan moon of Tethys, sharing Tethys's orbit at the L4 Lagrange point 60° ahead. Calypso (Tethys's other Trojan companion) trails at L5. The Tethys-Telesto-Calypso triple is one of the only known sets of co-orbital Trojan moons in the solar system.
Missions and observations
Every Saturn-system mission has had an opportunity to image or characterize Telesto. The list below is the Saturn-system mission catalog; specific Telesto encounters are documented in mission archives.
| Mission | Year at Saturn | Status |
|---|---|---|
|
Pioneer 11 NASA |
1979 | Completed |
|
Voyager 1 NASA |
1980 | Completed |
|
Voyager 2 NASA |
1981 | Completed |
|
Cassini-Huygens NASA/ESA/ASI |
2004 | Completed |
|
Dragonfly NASA |
2034 | On the way |
Naming etymology
Telesto was an Oceanid nymph, daughter of Tethys (the Titaness, hence the orbital naming pairing). The IAU adopted the name in 1983.
Methodology & sources
Diameter, mass, and orbital parameters from JPL Solar System Dynamics — Physical Parameters. Discovery year and discoverer from the JPL Satellite Discovery Circumstances. Naming etymology from the IAU Working Group for Planetary System Nomenclature. Stylized SVG hero composed from NASA / JPL imagery as visual reference; no photographs are reproduced.