20 June 2008
Credit: NASA/JPL/Space Science Institute
NASA’s Jet Propulsion Laboratory (JPL) recently published an interesting image of Rhea, Saturn’s second largest moon. Among the remarkable surface features recorded in the image are two large, ancient impact basins and a younger bright rayed crater.
The large basin above center is known as Tirawa. (Tirawa is the mythological creator god of the Pawnee people, a tribe of Native Americans.) Numerous smaller craters are overlaying this feature, and the similar-sized crater to its left, indicating it is an extremely old feature that has been bombarded with meteoroids over long periods of time.
This bright rayed crater appears to be a younger feature, as it possesses crisp edges, is not heavily overlapped by other craters, and the cover of bright, fresh material ejected by the impact is still visible. The illuminated terrain visible in this image is on the moon's anti-Saturn side. North on Rhea (1,528 km across) is up.
The image was taken in visible light with the Cassini spacecraft narrow-angle camera on 13 May 2008. The view was acquired at a distance of approximately 889,000 km from Rhea. Image scale is 5 km per pixel.
Further Reading
The Cassini-Huygens Mission to Saturn
http://saturn.jpl.nasa.gov/home/index.cfm
Saturn
http://www.nineplanets.org/saturn.html
Rhea
http://www.nineplanets.org/rhea.html
Aymen Mohamed Ibrahem
Senior Astronomy Specialist