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Space Topics: Saturn

Tethys

Chasm Moon

Tethys
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Tethys
Tethys as seen by Cassini on approach to its September 24, 2005 flyby. Ithaca Chasma stretches from Telemachus crater in the north, down to the south pole. It wraps around a large impact basin that has been so battered by subsequent craters as to be nearly invisible. Source Credit: NASA / JPL / Space Science Institute

Size: 1,072 x 1,056 x 1,052 kilometers - 5th largest moon of Saturn
Orbital radius: 294,660 kilometers - 4.88 Saturn radii
Orbital period: 1.888 days - about 1/8 of Titan’s
Discovery: 1684 by Giovanni Domenico Cassini

Like Mimas, Tethys has an enormous impact crater on one side, named Odysseus. But Odysseus is a very different crater from Herschel (the big crater on Mimas). While Herschel has very steep scarps, the floor of Odysseus is quite smooth in its topographic profile; the surface of Tethys has "relaxed" so that the crater floor follows the shape of the moon.

All of the features on Tethys draw their names from Homer's Odyssey. Curling across Tethys' surface is a gigantic canyon system called Ithaca Chasma. Views of Ithaca Chasma during a close flyby by Cassini show that it has been battered with impact craters, indicating that it is extremely old.

Two tiny rocks -- Telesto and Calypso -- share the same orbit around Saturn with Tethys. Telesto is in Tethys's leading Lagrange point orbiting 60 degrees ahead of Tethys, and Calypso is in Tethys's trailing Lagrange point, orbiting 60 degrees behind Tethys.

Flybys of Tethys

 


Map of Tethys

Global map of Tethys (simple cylindrical projection)
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Global map of Tethys (simple cylindrical projection)
Global map centered at 180 degrees longitude (the anti-Saturnian point). The map is 2,048 pixels wide, and Tethys' diameter is 1,060 kilometers, so the map resolution is 1.63 kilometers per pixel at the equator. A larger and more up-to-date version may be available at Steve Albers' website. Credit: NASA / JPL / Space Science Institute / Steve Albers