... Ithaca Chasma: The Great Rift on Saturns Tethys . ... Credit: Cassini Imaging Team , SSI , JPL , ESA , NASA Explanation: What created the Great Rift on Saturn's moon Tethys? ... Hypotheses for the formation of Ithaca Chasma include cracking of Tethy's outer crust as the moon cooled long ago, and that somehow the rift is related to the huge Great Basin impact crater named Odysseus , visible elsewhere on the unusual moon. ... The Great Basin on Saturns Tethys . ... Saturns Moon Tethys from Cassini . ...