"After over 10 years of the Cassini mission, this represents a capstone finding for the mission and means that Enceladus has nearly all of the ingredients you would need to support life here on Earth".
Thanks to Cassini, organic chemicals-carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur-which are the basic building blocks of life, were seen spraying forth from the "tiger stripe" cracks on the cold surface of the moon. If that is the case, then it is also reasonable to think that microbe life - if it exists - could be flourishing due to a process known as "methanogenesis".
Hydrogen was detected by Cassini's instruments in a massive plume of water that spouted from Enceladus' surface in 2015. Such a chemical reaction produces methane as a byproduct, and forms the root of Earth's own tree of life.
"Although we can't detect life, we've found that there's a food source there for it", said Hunter Waite, lead author of the Cassini study.
The hydrogen, which shoots out of the moon in high-powered ice jets, is the final puzzle piece following the discovery of its liquid ocean and carbon dioxide.
The probe found the hydrogen when it made its last and closest pass through plumes at Enceladus' south pole on October 28, 2015. "We have not found evidence of the presence of microbial life in the ocean of Enceladus, but the discovery of hydrogen gas and the evidence for ongoing hydrothermal activity offer a tantalizing suggestion that habitable conditions could exist beneath the moon's icy crust".More news: Facebook CEO Mark Zuckerberg addresses shooting controversy during San Jose F8 Conference
Several moons orbiting Jupiter and Saturn are known to contain underground oceans, but Enceladus is the only one where scientists have found proof of an energy source for life. The Cassini craft actually descended into the plume and sampled its makeup, finding chemical mix that included 98 percent water and 1 percent hydrogen, as well as traces of other gases like Carbon dioxide and methane.
A picture of the ice plumes on Enceladus taken by Cassini.
"If correct, this observation has fundamental implications for the possibility of life on Enceladus", Seewald wrote.
Here's why the finding of molecular hydrogen matters: It provides evidence that hot rocks and water are interacting under the moon's surface.
Jim Green, director, Planetary Science Division at NASA Headquarters, said NASA will continue to examine these oceans.
As for what's next, NASA will launch a Europa Clipper mission in the 2020s based off of the Hubble's monitoring of Europa, and Cassini's look into Enceladus' plume.