What is Tethys (moon)?
[[Image:Tethys cassini.jpg|right|thumb|Photo taken by [[Cassini-Huygens]].]] '''Tethys''' (pronounced ''TEE-this'')<ref name=NASAfact /><ref name=NASAfact3 /> is a large [[Satellite (natural)|moon]] of the planet [[Saturn (planet)|Saturn]]. == Discovery == It was discovered by [[Giovanni Domenico Cassini]] in 1684.<ref name=NASAfact>{{cite web|url=http://solarsystem.nasa.gov/planets/profile.cfm?Object=Sat_Tethys|author=Harvey, Samantha|publisher=NASA|date=2011-03-04|accessdate=2011-03-13|title=NASA: Solar System Exploration: Planets: Saturn: Moons: Tethys|archive-date=2007-06-09|archive-url=https://web.archive.org/web/20070609142406/http://solarsystem.nasa.gov/planets/profile.cfm?Object=Sat_Tethys|url-status=dead}}</ref><ref name=NASAfact3>{{cite web|title=NASA: Jet Propulsion Laboratory: Cassini Solstice Mission: About Saturn & Its Moons: Saturn's Moons: Tethys|url=http://saturn.jpl.nasa.gov/science/moons/tethys/|publisher=NASA|accessdate=2011-03-13|author=Piazza, Enrico|archive-date=2016-04-04|archive-url=https://web.archive.org/web/20160404145935/http://saturn.jpl.nasa.gov/science/moons/tethys/|url-status=dead}}</ref> It was one of the first Saturnian moons discovered. == Physical characteristics == === Mass, density and volume === Tethys' mass is 617,551,805,221,061,000,000 [[kg]], its [[density]] is 0.973 g/cm<sup>3</sup> and its [[volume]] is 634,264,255&nbsp;km<sup>3</sup>.<ref name=NASAfact2>{{cite web|url=http://solarsystem.nasa.gov/planets/profile.cfm?Object=Sat_Tethys&Display=Facts&System=Metric|author=Harvey, Samantha|publisher=NASA|date=2011-03-04|accessdate=2011-03-13|title=NASA: Solar System Exploration: Planets: Saturn: Moons: Tethys: Facts & Figures|archive-date=2010-05-31|archive-url=https://web.archive.org/web/20100531204648/http://solarsystem.nasa.gov/planets/profile.cfm?Object=Sat_Tethys&Display=Facts&System=Metric|url-status=dead}}</ref> === Craters and valleys === It has a very large [[crater]] on its [[surface]], called Odysseus.<ref name=NASAfact /> It is named after a [[Greece|Greek]]