25 July 2008
A picture of Tethys, Saturn’s icy moon, showing a giant impact crater, below center
Credit: NASA/JPL/Space Science Institute
NASA’s Jet Propulsion Laboratory (JPL) recently published an intriguing image of Saturn’s icy moon Tethys, acquired by the Saturn-bound Cassini spacecraft. Tethys (1,062 km across) sports an enormous impact basin, known as Odysseus. The impact basin is 450 km wide, and contains a central complex of mountains.
Like our Moon (3,476 km across), Tethys keeps the same side turned to its parent wonderful planet. Illuminated terrain visible here is on the leading hemisphere of Tethys. North is up.
The image was taken in visible light with the Cassini spacecraft narrow-angle camera on 31 May 2008. The view was obtained at a distance of approximately 717,000 km from Tethys. Image scale is 4 km per pixel.
Tethys orbits Saturn in a circular orbit of a radius of 295,000 km, every 1.9 days. Two small moons share Tethys its orbit. Interestingly, Tethys’ surface is extremely bright, reflecting most of the sunlight that strikes its surface. Therefore, Tethys resembles a huge mirror in space! In Greek mythology, Tethys was a sister of Cronus (Saturn) and a wife of Oceanus, the personification of the world ocean.
Further Reading
The Cassini-Huygens Mission to Saturn
http://saturn.jpl.nasa.gov/home/index.cfm
Aymen Mohamed Ibrahem
Senior Astronomy Specialist