New Earth? It Seems Scientists Have Found a Hidden Ocean in the Solar System “Capable of Providing a Large Amount of Energy to Any Life”
A recent investigation delves into the data collected by NASA’s Cassini at Saturn’s icy moon, revealing compelling evidence of a crucial ingredient for life and an energetically charged source to support it.
Previously, scientists knew that Enceladus, Saturn’s moon, emitted a substantial plume of ice grains and water vapor rich in organic compounds, some vital for life. Now, an analysis of NASA’s Cassini mission data takes the case for habitability a step further by confirming the presence of hydrogen cyanide, a molecule essential to life’s origins.
Published on December 14 in Nature Astronomy, these findings suggest that Enceladus may house more chemical energy than previously estimated. The increased availability of energy enhances the likelihood of life proliferation and sustainability.
Lead author Jonah Peter, a doctoral student at Harvard University, conducted much of the research at NASA’s Jet Propulsion Laboratory in Southern California.
The author added, “Our work provides further evidence that Enceladus is host to some of the most important molecules for both creating the building blocks of life and for sustaining that life through metabolic reactions.
“Not only does Enceladus seem to meet the basic requirements for habitability, we now have an idea about how complex biomolecules could form there, and what sort of chemical pathways might be involved.”
The revelation of hydrogen cyanide was especially thrilling as it serves as the foundational element in most theories concerning the origin of life.
The foundation of life, as we understand it, depends on essential building blocks like amino acids. Hydrogen cyanide emerges as a pivotal and versatile molecule crucial for the synthesis of amino acids. Given its ability to form diverse molecular configurations, the researchers describe hydrogen cyanide as the multifaceted tool akin to the Swiss army knife in the realm of amino acid precursors.
Peter further remarked, “The more we tried to poke holes in our results by testing alternative models, the stronger the evidence became. Eventually, it became clear that there is no way to match the plume composition without including hydrogen cyanide.”
In 2017, scientists identified chemical indications at Enceladus that could potentially sustain life in its ocean. The presence of carbon dioxide, methane, and hydrogen in the plume hinted at methanogenesis, a metabolic process producing methane. Methanogenesis is widespread on Earth and might have played a crucial role in the genesis of life on our planet.
The latest research reveals evidence of additional chemical energy sources that surpass the generation of methane in terms of both potency and diversity. The study identifies a variety of oxidized organic compounds, signaling to scientists that there are numerous chemical pathways within Enceladus’ subsurface ocean that could potentially sustain life. The process of oxidation plays a crucial role in releasing chemical energy.
Kevin Hand, co-author of the study and principal investigator of the research leading to these new findings at JPL, compares the energy potential, stating, “If methanogenesis is like a small watch battery, in terms of energy, then our results suggest the ocean of Enceladus might offer something more akin to a car battery, capable of providing a large amount of energy to any life that might be present.”
Unlike previous studies that relied on lab experiments and geochemical modeling to reproduce the conditions Cassini discovered on Enceladus, the current study relied on rigorous statistical analysis.
They scrutinized data collected by Cassini’s ion and neutral mass spectrometer, which examined the gas, ions, and ice grains in Saturn’s vicinity.
Through quantifying the information within the data, the team discerned subtle variations in how effectively different chemical compounds accounted for the Cassini signal.
The Lead author Peter, “There are many potential puzzle pieces that can be fit together when trying to match the observed data. We used math and statistical modeling to figure out which combination of puzzle pieces best matches the plume composition and makes the most of the data, without overinterpreting the limited dataset.”
While the question of whether life could originate on Enceladus remains unanswered, Peter highlighted that the study outlines chemical pathways for life that can be experimentally tested.
Meanwhile, the Cassini mission continues to yield valuable insights, even after its revelation that Enceladus is an active moon. In 2017, the mission concluded by intentionally directing the spacecraft into Saturn’s atmosphere. Tom Nordheim, a JPL planetary scientist and co-author of the study, remarked, “Our study demonstrates that while Cassini’s mission has ended, its observations continue to provide us with new insights about Saturn and its moons – including the enigmatic Enceladus.”
Image Credit: NASA