Enceladus, one of Saturn's moons, is a veritable heat factory, pumping out heat energy equivalent to 20 coal-fueled power stations, U.S. researchers say.

Scientists say a new analysis of data collected by NASA's Cassini spacecraft shows the heat energy from the south polar region of Enceladus is much greater than was previously thought possible. ScienceDaily.com reported Wednesday.

Data on the polar terrain, which is marked by linear fissures, indicate the internal heat-generated power is about 15.8 gigawatts, about 2.6 times the power output of all the hot springs in the Yellowstone National Park region.

Researchers have known since 2005 the region is geologically active, centered on four roughly parallel linear trenches, 80 miles long and about a mile wide, dubbed by scientists as the "tiger stripes."

These fissures, with elevated temperatures due to heat leaking out of Enceladus' interior, eject great plumes of ice particles and water vapor continually into space.

"The mechanism capable of producing the much higher observed internal power remains a mystery and challenges the currently proposed models of long-term heat production," said Carly Howett, a postdoctoral researcher at Southwest Research Institute in Boulder, Colo., and a Cassini science team member.

Recently, it was discovered some of the ejected ice particles are salt-rich, and are probably frozen droplets from a saltwater ocean in contact with Enceladus' mineral-rich rocky core.

"The possibility of liquid water, a tidal energy source and the observation of organic (carbon-rich) chemicals in the plume of Enceladus make the satellite a site of strong astrobiological interest," Howett said.