Tethys is made almost entirely of water ice. It's barely denser than water.
A canyon called Ithaca Chasma runs about three-quarters of the way around it, up to 100 km wide and several kilometres deep.
On the other side is Odysseus, a crater about 450 km across, almost half the width of the moon.
Tethys shares its orbit with two tiny moons, one riding ahead of it and one behind.
If you stood here
Water ice as hard as rock under your feet, at about −187 °C, and Saturn's rings seen almost edge-on.
- Width
- 1,062 km
- Goes round Saturn
- every 45 hours
- One day
- The same: it always shows Saturn one face
- Temperature
- about −187 °C
- 70 kg on Earth weighs
- 1 kg here
