As a final hurrah before being plunged into Saturn, Cassini has now proven that Oceans that could hold the ingredients for life exist on a world other than our own.
Papers now published from both Cassini and Hubble missions conclude that a ‘form of chemical energy that life can feed on appears to exist on Saturn’s moon Enceladus’. Whereas, meanwhile on Jupiter’s moon Europa, the Hubble Space Telescope now has evidence of ‘plumes erupting’.
Evidence of this scale doesn’t prove that there is in fact life lurking in the oceans of Europa and Enceladus – what it does show is that the ingredients are there and future missions can now be directed to proving the origin of life on both Moons.
This is the closest we've come, so far, to identifying a place with some of the ingredients needed for a habitable environment. These results demonstrate the interconnected nature of NASA's science missions that are getting us closer to answering whether we are indeed alone or not.
Thomas Zurbuchen, associate administrator for NASA's Science Mission Directorate.
Ingredients for life consist of ‘liquid water, a source of energy for metabolism and the right chemical ingredients, primarily carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur’. Evidence from Cassini has shown that nearly all of these ingredients are present on Enceladus although have yet to prove the presence of phosphorus and sulfur – which doesn’t mean that it’s not there, they just haven’t found it yet.
Confirmation that the chemical energy for life exists within the ocean of a small moon of Saturn is an important milestone in our search for habitable worlds beyond Earth.
Linda Spilker, Cassini project scientist at NASA’s Jet Propulsion Laboratory (JPL).
Using Cassini's Ion and Neutral Mass Spectrometer, which essentially ‘sniffs’ gases to determine their composition the mission was originally supposed to be focusing on the atmosphere of Titan, however, shifted its focus to Enceladus after detecting a plume of gas and ice in 2005.
Unfortunately, the mission was not designed to detect signs of life however, it can detect that the ingredients are there for it and that there is a food source for it, albeit for microbial life.
These findings have concluded that hydrothermal activity is taking place in the oceans of Enceladus and that the hot water is reacting with the rocks beneath the ocean which are then reacting to produce hydrogen.
If there are plumes on Europa, as we now strongly suspect, with the Europa Clipper we will be ready for them.
Jim Green, Director of Planetary Science, at NASA Headquarters.
From the discoveries on Europa, there is a mission planned to launch sometime in the 2020’s with the task of developing next generation spectrometers with higher sensitivity as well as having an ultraviolet camera that can essentially fly through these plumes and hopefully detect that life does exist beneath the oceans of Europa.
Now that similar findings have been reported from Enceladus, the focus may turn to the small moon of Saturn where, millions of miles away, there may be the existence of life on another world.
Image Credit: NASA/JPL-Caltech