Abstract
SAN FRANCISCO, CALIFORNIA—Why is there geology on Saturn's icy satellites? Where did these smallish moons get the energy to refresh their impact-battered surfaces with smoothed plains, ridges, and fissures? These questions have nagged at scientists since the Voyager flybys in the early 1980s, and the Cassini spacecraft's recent discovery that Saturn's Enceladus is spouting like an icy geyser has only compounded the problem (Science, 9 September 2005, p. 1660). Now a group of Cassini team members puzzling over the odd shape of the satellite Iapetus has hit on a possible explanation. Perhaps the moons formed early and grabbed just enough heat-generating radioactivity from the nascent solar system.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
