Conditions for life may exist on moon of Saturn

Scientists say one of Saturn's outer rings was actually formed from hydrogen rich water and ice being released from Enceladus.

NASA's Cassini spacecraft detected the presence of molecular hydrogen in water plumes erupting from Saturn's icy moon Enceladus, the US space agency announced Thursday, suggesting that the distant world has nearly all the conditions necessary for life.

According to Cassini mission researchers, hydrogen gas - a building block of life - has been detected pouring into the subsurface of the ocean of Enceladus as an outcome of the activity taking place on its seafloor.

David Rothery, Professor of Planetary Geosciences at the Open University, added: "Life has not been discovered on Enceladus, but we do now have the last piece of evidence needed to demonstrate that life is possible there". Either way the implications are profound.

[Enceladus is the] closest we've come, so far, to identifying a place with some of the ingredients needed for a habitable environment.

The search for alien life where there is potential includes at least two of Saturn's moons, Enceladus and Titan.

An artist's rendering showing Cassini diving through the plume on Enceladus in 2015. The heavy presence of hydrogen suggests chemical reactions between the warm water and ocean-floor rock that could support life.

There are three essential ingredients for life: water, a source of energy for metabolism, and a mixture of carbon, hydrogen, nitrogen, oxygen, phosphorus and sulphur.

It was during Cassini's flyby of Enceladus in 2015 that the Ion Neutral Mass Spectrometer (INMS) detected molecular hydrogen as the spacecraft flew through a plume of vapor ejected from the moon's surface. The researchers reported that the hydrogen, along with carbon dioxide that was also found, could mean that undersea microbes are producing methane as they do in the bowels of our own oceans and waterways. The final results were published in the journal Science.

A decade later, scientists measuring the moon's slightly wobbly orbit around Saturn determined it holds a vast ocean buried 19- to 25 miles (30- to 40 km) beneath its icy shell. A possible plume of material has also been spotted erupting from the surface of Europa previous year, in the same place that one was spotted by Hubble in 2014. It took another 10 years, in 2014, for the orbiter to start reporting in some rather interesting findings coming from Saturn's moon, Enceladus.

Data collected by the Cassini spacecraft above Saturn's moon Enceladus suggest a similar environment to that which gave rise to life on Earth.

As the lead author Hunter Waite put it, the reaction would basically provide a "candy store for microbes". Both correspond to the location of an unusually warm region that contains features that appear to be cracks in the moon's icy crust, seen in the late 1990s by NASA's Galileo spacecraft.

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. The most recent survey ranked Europa second, however, behind a series of missions to return a sample of Mars to Earth. Hubble has helped show that Europa also harbors its own globe-spanning ocean.

  • Tracy Ferguson