Saturn's gravitational pull creates scalding geyser on the planet's moon, Enceladus. The force of the geysers depends on the proximity of the moon to Saturn.
The geysers suggest there may be a large reservoir or ocean beneath the moon's frozen surface, a NASA press release reported.
This finding marks the first solid observation of the plumes.
"The jets of Enceladus apparently work like adjustable garden hose nozzles," Matt Hedman, lead author of the paper and a Cassini team scientist from Cornell University, said, "The nozzles are almost closed when Enceladus is closer to Saturn and are most open when the moon is farthest away. We think this has to do with how Saturn squeezes and releases the moon with its gravity."
The Cassini satellite first discovered the jets in 2005. Cassini observed that the geysers shoot out from active fissures in the moon's surface called "tiger stripes." The jets are possibly composed of water and organic particles.
"The way the jets react so responsively to changing stresses on Enceladus suggests they have their origins in a large body of liquid water," Christophe Sotin, a co-author and Cassini team member at NASA's Jet Propulsion Laboratory, said. "Liquid water was key to the development of life on Earth, so these discoveries whet the appetite to know whether life exists everywhere water is present."
Scientists have known the jets varied in intensity for years but they have only recently attributed this change to Saturn's gravitational pull. The team identified the pattern using infrared data.
When the moon was farthest from the planet the plume was three to four times brighter than when it was its closest point.
"This is comparable to moving from a dim hallway into a brightly lit office," the release reported.
The scientists concluded that when Enceladus was under a tighter gravitational "squeeze" the openings in the tiger stripes were narrower. When the moon moves farther from Saturn, the cracks become wider, allowing more "water" to escape.
"Cassini's time at Saturn has shown us how active and kaleidoscopic this planet, its rings and its moons are," Linda Spilker, a Cassini project scientist, said."We've come a long way from the placid-looking Saturn that Galileo first spied through his telescope. We hope to learn more about the forces at work here as a microcosm for how our solar system formed."
