New evidence from NASA suggests Saturn’s moon Enceladus may not be as hostile and inhospitable as it seems. Nasa’s Cassini spacecraft has picked up the first evidence that chemical reactions are happening deep below the ice which could be creating an environment capable of supporting microbes.
Liquid oceans exist miles below the surface on Enceladus, so to find out what is happening in the underground seas scientists must rely on the plumes of spray which shoot up into the atmosphere through cracks in the ice.
Life could be thriving in warm underground seas, scientists believe. All the more remarkable is that, this moon 887 million miles away from the Sun, might be harbouring the perfect conditions for life.
In October 2015 Nasa sent Cassini into a deep dive through one of those plumes and discovered hydrogen and carbon dioxide. In a report of their findings published today in the journal Science, scientists said that the ‘only plausible’ source for the hydrogen was chemical reactions between warm water and rocks on the ocean floor.
“Saturn’s moon Enceladus has an ice-covered ocean, and a plume of material erupts from cracks in the ice,” said Professor Hunter Waite, of Southwest Research Institute (SwRI) in San Antonio, Principal Investigator for Cassini’s Mass Spectrometer instrument which detected the hydrogen.
“The plume contains chemical signatures of water-rock interaction between the ocean and a rocky core. We find that the most plausible source of this hydrogen is ongoing hydrothermal reactions of rock containing reduced minerals and organic materials.
“On the modern Earth, geochemically derived fuels such as hydrogen support thriving ecosystems even in the absence of sunlight.”
Scientists had long suspected that liquid water could exist on the moon because of the extreme tidal forces acting on the satellite from Saturn’s gravity. Crucially, if hydrogen is present it can mix with carbon dioxide to form methane, which is consumed by microbes in the deep, dark seas of our own planet. If life is present, it could resemble single-celled tube-like extremophiles which have lived in hydrothermal vents on Earth for billions of years.
