02 December 2010
A close-up view of Enceladus, Saturn’s small volcanic moon
The image, acquired by the Saturn-bound Cassini spacecraft, shows plumes of icy material, emanating from the south polar region of Enceladus.
Credit: NASA/JPL/SSI
On 30 November 2010, NASA’s Saturn-orbiting Cassini spacecraft flew by Enceladus, a small geologically-active Saturnian moon. Cassini approached Enceladus (504 km across) to within only 48 km, and imaged the bright plumes of icy material that erupt from fissures in the southern polar region of the moon.
Enceladus’ plumes, consisting of water vapor and icy particles, are unique among planetary moons. They are the result of a rare, intriguing type of volcanism, known as cryovolcanoes. Cryovolcanoes erupt very cold material, instead of lava. Cassini discovered these plumes in 2005.
During the flyby, sophisticated instruments aboard Cassini acquired gravity data to study Enceladus' internal structure, and sampled the charged particles around the moon.
About two days earlier, Cassini also observed another wonder of the Saturn system, a bizarre, small moon, known as Hyperion, sending back intriguing images of the craters on its surface. Hyperion is irregular in shape, not round. Its rugged weird terrain, including deep, sharp-edged craters, resembles sponge. Cassini passed 72,000 km from Hyperion.
Scientists are still working to analyze the data and images collected during the two flybys.
Further Reading
Cassini Mission Homepage
http://saturn.jpl.nasa.gov/
Aymen Mohamed Ibrahem
Senior Astronomy Specialist