HOUSTON, March 13 U.S. scientists think they have figured out why one of Saturn's moons has watery geysers.Researchers from NASA's Jet Propulsion Laboratory in California say soon after Enceladus formed 4.5 billion years ago, a radioactive burst created a molten core providing heat that produced conditions for geysers first detected in 2005, the BBC said Tuesday.Dennis Matson and Julie Castillo-Rogez presented their findings at the Lunar and Planetary Sciences conference in Houston.Matson said the moon's core temperatures could have been as high as 1,340 degrees Fahrenheit. Castillo-Rogez said the only way that could have happened was through the rapid decay of some radioactive species.Enceladus consists of ice and rock containing radioactive isotopes aluminum-26 and iron-60. According to the model, those isotopes decayed over about seven million years, melting surface ice causing the rocky material to sink and form the moon's core. Other effects such as slower-decaying radioactivity and Saturn's gravitational pull, may be keeping the water warm, they said.The presence of a heat source, liquid water and other organic chemicals means Enceladus has the key ingredients for life.Copyright 2007 by UPI
