NASA’s missions provide new insights into the ocean worlds present in our solar system - specifically in the icy, oceans of Jupiter’s and Saturn’s moons. As a final hurrah before being plunged into Saturn, spacecraft Cassini shows that oceans on its moon holding ‘ingredients’ for life do exist on a world other than our own. The Hubble space telescope has found similar evidence of plumes erupting from the cracks in the icy surface of Jupiter’s moon Europa.
As part of one of the most ambitious planetary space exploration, spacecraft Cassini was launched on Oct 15, 1997. It took 7 years for it to reach Saturn and the mission ended on Sept 15, 2017. It was orbiting Saturn: to study the Saturnian system and its moons in great detail. Though the mission was not designed to detect signs of life, however, it detected that the ingredients for life are there.
Cassini’s discovery of ocean worlds at Titan and Enceladus changed everything, shaking our views to the core about surprising places to search for potential life beyond Earth.
Thomas Zurbuchen, associate administrator for NASA's Science Mission Directorate, at NASA Headquarters in Washington.
Research 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’. Meanwhile on Jupiter’s moon Europa, the Hubble Space Telescope now has evidence of ‘plumes erupting’.
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).
Because the location of plumes on Europa correspond to the location of eruption of plumes on Enceladus – sitting right on the ‘thermal anomaly’ – researchers speculate that it could be evidence of water erupting from the moon’s interior.
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, the presence of phosphorus and sulfur is yet to be established, it does not mean that these elements are not there; maybe they have just not found it yet.
The Cassini mission was originally supposed to be focusing on the atmosphere of Titan. However, it shifted its focus to Enceladus after detecting a plume of gas and ice in 2005. 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.
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 any origins of life on both moons.
Recently, based on data from spacecraft Cassini, researchers show the presence of ‘large and complex organic molecules’ in the ejected water vapor and ice grains from the massive subsurface ocean. This finding reinforces the idea that these intriguing ocean worlds could support a habitable environment for life. Cassini has dove finally into the atmosphere of Saturn; however, with its data, discoveries and the science will continue.
Millions of miles away, there may be the existence of life on another world. With a food source and a habitable place available for microbial life in the distant oceans, maybe life is lurking there for us to discover it!
- Image Credit: NASA/JPL-Caltech
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This article was updated on 1st March, 2019.