USA
Today: Saturn's geyser-spewing moon,
Enceladus—visited
by the international
Cassini spacecraft on its closest flyby this
week—presents planetary scientists with a geophysical
locked-room mystery.How does something buried inside an ice
ball only 500 kilometers wide provide the pop to propel a plume
965 kilometers out of the moon's south pole?"The biggest puzzle
with Enceladus is where is the heat source," says
Cassini scientist
Linda
Spilker of
NASA's Jet Propulsion
Laboratory, which manages the mission. "This tiny moon
'should' be frozen over like the others orbiting Saturn."
