Editing Ithaca Chasma (section)

{{Short description|Major valley system on Tethys}}
{{Use dmy dates|date=May 2024}}
[[File:Tethys PIA07738.jpg|thumb|Tethys and Ithaca Chasma]]
'''Ithaca Chasma''' {{IPAc-en|'|I|T|@|k|@|_|'|k|ae|z|m|@}} is a valley ([[graben]]) of [[Saturn]]'s [[Moons of Saturn|moon]] [[Tethys (moon)|Tethys]], named after the island of [[Ithaca (island)|Ithaca]], in [[Greece]].{{sfn|USGS: Tethys: Ithaca Chasma}} It is up to {{convert|100|km|abbr=on}}  wide, {{convert|3-5|km|abbr=on}} deep and {{convert|2000|km|abbr=on}} long, running approximately three-quarters of the way around Tethys's circumference, making it one of the [[List of largest rifts and valleys in the Solar System|longer valleys in the Solar System]].  Ithaca Chasma is approximately concentric with [[Odysseus (crater)|Odysseus crater]].{{sfn|Moore Schenk et al.|2004|pp=424–30}}

Ithaca Chasma may have originated when the global salt water ocean inside Tethys froze. This would have caused the surface to crack in order to accommodate the resulting increase in volume. Another hypothesis is that Ithaca Chasma is the outermost ring of the Odysseus impact basin; however the chasma is from 4 to 0.4 billion years old, making it slightly older than Odysseus.