The Great Basin on Tethys . ... Credit Copyright: Cassini Imaging Team , SSI , JPL , ESA , NASA Explanation: Some moons wouldn't survive the collision. Tethys , one of Saturn's larger moons at about 1000 kilometers in diameter, survived the collision, but sports today the expansive impact crater Odysseus. Sometimes called the Great Basin, Odysseus occurs on the leading hemisphere of Tethys and shows its great age by the relative amount of smaller craters that occur inside its towering walls . ...