Changes in the starlight's intensity allowed the scientists to "see" four distinct high-density jets of steam within the broader clouds of gas, said team member Larry Esposito of the University of Colorado at Boulder.
Despite the jets' high speed, researchers calculated that the density and size of materials mean "the gas and particles are not a danger to Cassini," Esposito said.
Scientists slated the probe to fly through the plumes at an angle, approaching from the north and skirting southward along the edge.
The flyby gave scientists the most detailed view yet of heat coming from the tiger stripes.
Cassini's first Enceladus flyby in March of 2005 had captured images showing that the area around the fractures was much warmer than the surrounding surfaces.
"There was a very bright glow of heat coming out of the south polar region" in the 2005 images, Cassini co-investigator John Spencer of the Southwest Research Institute in Boulder, Colorado, said at the briefing.
(Related news: "Saturn's Icy Moon May Have Been Hot Enough for Life, Study Finds" [March 13, 2007].)
With the latest flyby, "now we see heat coming out of each of those fractures individually."
In fact, the warmest points along the fractures correspond to where two of the four jets originate.
Of course, warmth is a relative term on a moon like Enceladus, Spencer said.
The fractures are about -135 degrees Fahrenheit (-93 degrees Celsius)—downright balmy compared with the surrounding temperature of -300 degrees Fahrenheit (-184 degrees Celsius).
But the fact that heat is escaping through the tiger stripes suggests that it's even warmer under the moon's surface, he said.
"It's entirely possible there's going to be liquid water not too far below these tiger stripe fractures."
Unfortunately, a software glitch prevented the craft's Cosmic Dust Analyzer from taking measurements during the closest part of the approach.
Researchers had hoped that the instrument would collect better data on particles of sodium and silicon detected in the plumes during previous observations, Esposito told National Geographic News.
The probe also couldn't take new close-up visible-light images of the moon, Spencer said, because the flyby happened as Enceladus passed into Saturn's shadow.
"The lights went out, so we couldn't take any pictures—at least not any good ones," he said.
Two upcoming Enceladus flybys in October will therefore be dedicated to dust sampling and imaging.
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