An ice-encrusted moon orbiting Saturn appears to have the conditions necessary for life, NASA announced Thursday, unveiling new findings made by its unmanned Cassini spacecraft.
Cassini has detected hydrogen molecules in vapour plumes emanating from cracks in the surface of Enceladus, a small ocean moon coated in a thick layer of ice, the US space agency said. The plumes have led scientists to infer that hydrothermal chemical reactions between the moon’s rocky core and its ocean – located under the ice crust – are likely occurring on Enceladus.
On Earth, those chemical reactions allow microbes to flourish in hot cracks in the planet’s ocean floors — depths sunlight cannot reach — meaning the moon could also nourish life. The new research, published on Thursday in the journal Science, “indicates there is chemical potential to support microbial systems,” he said.
The hydrogen detection resulted from Cassini’s October 2015 deep dive close to the surface of Enceladus. Using a spectrometer, the spacecraft determined that the plumes are 98% water and one percent hydrogen, with traces of molecules including ammonia, carbon dioxide and methane.
Hydrogen had previously been “elusive,” scientists said, but its detection shows the moon’s life-supporting potential.
The hydrogen in the sub-surface ocean could combine with carbon dioxide molecules in a process known as “methanogenesis,” which creates a byproduct of methane. If there are indeed microbes living in the moon’s ocean, they could tap that energy source as sustenance.