Enceladus, Saturn’ small geologically-active moon
This image was acquired by the Saturn-bound Cassini spacecraft. It shows plumes of icy material, emanating from the south polar region of Enceladus, which shines as a slender crescent. These plumes are an intriguing phenomenon of a rare type of volcanoes, known as ice volcanoes.
Credit: NASA/JPL/Space Science Institute
NASA recently published a wonderful image of Enceladus, Saturn’s icy, geologically-active moon. The image was acquired by the Saturn-orbiting Cassini spacecraft. Enceladus (504 km across), shining in the crescent phase, is characterized by a rare type of volcanic activity, known as ice volcanoes, or cryovolcanoes. Ice volcanoes spew icy material and very cold vapors, rather than lavas! In the image, plumes of water ice emanate from fissures located in Enceladus’ south polar region.
The image was taken in visual light, with the narrow-angle camera instrument, on 30 January 2011. Cassini was at a distance of approximately 228,000 km from Enceladus.
Enceladus orbits Saturn every 1.37 days, at a distance of approximately 240,000 km. For comparison, the Moon (3,476 km across) orbits Earth every 27.3 days, at an average distance of about 384,000 km. Also, like our Moon, Enceladus keeps the same side turned to its planet. Its name comes from Greek mythology.
The Cassini mission is one of the largest scientific projects in history, with a budget of over US$3bn. Cassini was launched toward Saturn on 15 October 1997. It reached Saturn, and entered orbit around it, on 1 July 2004, to begin a detailed study of the planet and its moons. It is scheduled the Cassini mission will continue until 2017. The spacecraft was named in honor of Giovanni Cassini (1625-1712), the Italian astronomer, who discovered four moons of Saturn, and made great contributions to planetary astronomy.
Further Reading
Cassini Mission Homepage
http://saturn.jpl.nasa.gov/index.cfm
References
NASA’s Photojournal
NASA
www.nasa.gov/
Wikipedia