National Geographic News
Water, heat, and now organic materials—three of the basic ingredients for life as we know it—have all been confirmed on Saturn's moon Enceladus, scientists announced today.
The new data come from the closest flyby of the moon yet by NASA's Cassini spacecraft.
The probe flew through the plumes of ice and gas that jet out of Enceladus's south polar region on March 12, skimming just 32.3 miles (52 kilometers) above the surface.
"The density [of material] increased dramatically as we moved over the plume," Cassini team member Hunter Waite, of the Southwest Research Institute in San Antonio, Texas, said at a press briefing. "But water was not the only constituent we saw."
The probe also "tasted" methane and other organics within the jets at levels 20 times higher than expected, as well as carbon monoxide and carbon dioxide.
"The composition of the plume is very much like the composition of a comet," Waite noted.
Comets can contain primordial materials, so many scientists think the objects might have seeded life on Earth.
The presence of similar materials on Enceladus therefore raises questions about the possibilities for life within the Saturnian system, he said.
Before the flyby, scientists had used ultraviolet imaging on board Cassini to study the structure and composition of the plume and decide whether it would be safe for the craft to fly through.
Previous studies had revealed that plumes are shooting out of the moon at about 650 to 1,100 miles (1,046 to 1,770 kilometers) an hour, originating from fractures at the south pole known as tiger stripes.
Last October the team watched as a transiting star called zeta Orionis moved behind the gassy plumes.
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