Odysseus (crater)

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Odysseus is the largest crater on Saturn's moon Tethys. It is 400 km in diameter, 2/5 of the moon's total size. It is named after the Greek hero Odysseus.

The moon itself was named after the Greek mythological giantess Tethys; the moon is also known as Saturn III or S III Tethys. Odysseus is a very shallow crater. The crater must have originally been deep, with a high mountainous rim and towering central peak. Over time the crater floor has relaxed to the spherical shape of the Tethys's surface, and the crater's rim and central peak have collapsed (similar relaxation is apparent on Jupiter's moons Callisto and Ganymede). This indicates that at the time of the Odysseus impact, Tethys must have been sufficiently warm and malleable to allow the topography to collapse; its interior may have even been liquid. If Tethys had been colder and more brittle at the time of impact, the moon might have been shattered, and even if it survived the impact, the topography of the crater would have retained its shape similar to the crater Herschel on Mimas.

On the opposite side of Tethys from Odysseus is the immense trench Ithaca Chasma, which may have formed as a result of the Odysseus impact. Giovanni Domenico Cassini discovered the moon in 1684. The moon's average surface temperature is -187°C. Because of this, the moon is a frozen wasteland. The Image to the right was taken by The Voyager 2 spacecraft on August 25, 1981. Seeing that the craft was 826,000 kilometers away, it excluded the most right edge of the moon.