Saturns Moons Are Bustin Out All Over
Add Tethys and Dione to the party blowers around Saturn. Cassini found that these two moons are active, like Enceladus and Titan, though on a lesser scale. Cassini scientists discovered the effects of outbound particles from these moons by studying the plasma fields with the Cassini plasma spectrometer (CAPS) instrument. The results suggest surface activity, possibly even volcanic, on the two icy bodies that lie between Enceladus and Rhea.
The story, based on a paper in Nature,1 was picked up by Space.com, MSNBC and Science Daily.
1Burch et al, “Tethys and Dione as sources of outward-flowing plasma in Saturn’s magnetosphere,” Nature 447, 833-835 (14 June 2007) | doi:10.1038/nature05906.
This compounds the mystery of why these icy moons, so distant from the sun (and assumed to be so very, very old), should be active today when we can observe them up close. Cassini has been worth every penny just to see the surprised look on the scientists’ faces.
Stay tuned for the super-closeup flyby of Iapetus (03/01/2006, 01/07/2005) on September 10. More wonders are sure to be in the wings of the rings.