Telesto

astronomy

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July 14, 2026

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Telesto is one of Saturn's moons, discovered in 1684 by Gian Domenico Cassini. It is composed primarily of water ice and has a density similar to water. Telesto is a "Trojan" moon, meaning it shares its orbit with a larger moon, Tethys, maintaining a stable position 60 degrees ahead of Tethys.12

Telesto is accompanied by another small moon, Calypso, which occupies a similar stable position 60 degrees behind Tethys. These moons are part of Saturn's complex system of rings and moons, where their gravitational interactions can influence ring particles.123

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Saturn
Orbital and rotational dynamics
Instead, Tethys’s two co-orbiters, Telesto and Calypso, are located at the stable Lagrangian points along Tethys’s orbit, leading and following Tethys by 60°, respectively, analogous to the Trojan asteroids in Jupiter’s orbit. Dione’s Trojan-like companions, Helene and Polydeuces, lead and follow it by 60°, respectively, on average.
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Instead, Tethys’s two co-orbiters, Telesto and Calypso, are located at the stable Lagrangian points along Tethys’s orbit, leading and following Tethys by 60°, respectively, analogous to the Trojan asteroids in Jupiter’s orbit. Dione’s Trojan-like companions, Helene and Polydeuces, lead and follow it by 60°, respectively, on average.
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Tethys
…accompanied by two tiny moons, Telesto and Calypso (named for daughters of Titans), that maintain gravitationally stable positions along its orbit, analogous to Jupiter’s Trojan asteroids. Telesto precedes Tethys by 60°, and Calypso follows by 60°. (For comparative data about Tethys, its companions, and other Saturnian satellites, see the table.)
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…accompanied by two tiny moons, Telesto and Calypso (named for daughters of Titans), that maintain gravitationally stable positions along its orbit, analogous to Jupiter’s Trojan asteroids. Telesto precedes Tethys by 60°, and Calypso follows by 60°. (For comparative data about Tethys, its companions, and other Saturnian satellites, see the table.)
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