NASA announces that Saturn's moon could support life

A vast ocean - believed to be the source of the geysers - is said to be buried between 19 and 25 miles (30-40 km) beneath Enceladus' icy shell. Since repeatability is key in science, those findings were put on the back burner.

"This is the closest we've come, so far, to identifying a place with some of the ingredients needed for a habitable environment", Thomas Zurbuchen, associate administrator for NASA's Science Mission Directorate, said during the NASA teleconference. Recent evidence also suggested the water percolates into cracks and fissures in the rocky seafloor. "Our results indicate the same chemical energy source is present in the ocean of Enceladus". Cassini detected molecular hydrogen and methane within the vapor - chemicals typically found naturally in hydrothermal vents at the bottom of Earth's oceans.

"Cassini and Enceladus really allowed us to see the kind of things we could do with mass spectrometers and, more importantly, with material that's coming up straight out of the ocean", Waite said. The Cassini spacecraft detected hydrogen emanating from the planet while passing through that body's plume on several fly-by maneuvers.

"Some of the most primitive metabolic pathways utilized by microbes in these environments involve the reduction of carbon dioxide (CO2) with H2 to form methane (CH4) by a process known as methanogenesis", Jeffrey Seewald wrote in an accompanying piece in the same Science magazine.

As the lead author Hunter Waite put it, the reaction would basically provide a "candy store for microbes". This is the second time a plume has been observed in this exact spot, which has researchers excited that it could prove to be a feature on the surface. For a decade, Enceladus was the only icy moon where this was known to happen, but plumes have recently been found on Europa, too, a larger icy moon of Jupiter.

A press conference viewer, asking questions of the scientists via Twitter, asked if NASA was talking about bacteria or algae - or giant squids. Those traces are all signs of the presence of life as we know it. "And part of that could be that we think Enceladus might be fairly young".

An illustration of Cassini, a NASA spacecraft, above the surface of Saturn's moon Enceladus. And there's "no reason" why the same process wouldn't be happening on the moon orbiting Jupiter, Voytek says. Enceladus and its warm hydrothermal vents could be the place where we one day find life.

The Europa Clipper will be equipped with a powerful ultraviolet imaging system that will be able to make close-up, high-resolution observations that should reveal the nature of the presumed plumes and whether they represent water escaping through the surface cracks.

It's going to take years for scientists to definitively determine whether there is life on either moon.

Scientists will have a chance to explore Europa's watery world as NASA prepares for the Europa Clipper mission. With the end of the Cassini mission scheduled for this September, the next step in the study of Enceladus and the understanding its habitability would probably be the design of a mission dedicated to the study of the satellite and the analysis of its jets.

Cassini's INMS was devised to sample the upper atmosphere of Saturn's moon Titan.

  • Salvatore Jensen