Who discovered Tethys moon of Saturn and when?
Tethys was discovered by Giovanni Domenico Cassini in 1684, on the same occasion he found Dione. Cassini made the observation using a large aerial telescope at the Paris Observatory.
Questions about Tethys (moon)
Short answers, pulled from the story.
Why is Tethys moon so bright and reflective?
Tethys has a visual albedo of 1.229, one of the highest in the Solar System. Its brightness comes from a surface composed of nearly pure water ice, continuously refreshed by ice particles blasted from Saturn's E-ring, which itself is fed by geysers on Enceladus.
How large is Odysseus crater on Tethys?
Odysseus crater is about 450 km in diameter, nearly two-fifths of the total diameter of Tethys itself. Its rim rises approximately 5 km above the mean satellite radius, and the central massifs stand 6-9 km above the crater floor.
What is Ithaca Chasma on Tethys moon?
Ithaca Chasma is a vast valley on Tethys about 100 km wide, 3 km deep, and more than 2,000 km long, running approximately three-quarters of the way around the moon. It occupies roughly 10 percent of Tethys's surface and is thought to have formed when an internal ocean froze and the expanding ice cracked the crust.
What spacecraft have visited Tethys moon?
Tethys has been visited by Pioneer 11 in 1979, Voyager 1 in 1980, Voyager 2 in 1981, and the Cassini spacecraft during its 2004-2017 mission to Saturn. Cassini's closest targeted flyby on the 24th of September 2005 passed within 1,503 km of the surface.
What is Tethys moon made of?
Tethys is composed almost entirely of water ice. Its density of 0.98 g/cm3 is the lowest of all major moons in the Solar System, and spectroscopy has confirmed that crystalline water ice is the dominant surface material. Small amounts of an unidentified dark material, likely nanophase iron or hematite, are also present.