2023-12-15 09:45:21
A new study, in which the data that the Cassini space probe collected while flying over Enceladus, one of the moons of the planet Saturn, has been reanalyzed, has made it possible to find evidence of the abundance on Enceladus of a key ingredient for life and existence. of a large source of energy to sustain said life.
It was already known, for a few years, that a gigantic plume of ice grains and water vapor, ejected from the subsurface of Enceladus, is rich in organic compounds, some of which are important for life as we know it. Now, scientists who have delved into the data from the Cassini mission have gone one step further: they have found solid confirmation of the presence of hydrogen cyanide, a key substance for the emergence of life.
Researchers have also found evidence that the ocean beneath the moon’s icy outer shell that feeds the plume harbors a rich source of chemical energy. Unidentified until now, the energy source comes in the form of various organic compounds, some of which, on Earth, serve as fuel for organisms.
The discovery indicates that there may be much more chemical energy inside this tiny moon than previously thought. The more energy available, the more likely life is to emerge, proliferate, and sustain itself.
“Our research provides further evidence that Enceladus harbors some of the most important molecules for both creating the building blocks of life and sustaining that life through metabolic reactions,” said study lead author Jonah Peter of Harvard University in United States, which performed much of the work while at NASA’s Jet Propulsion Laboratory (JPL) in Southern California. “Not only does Enceladus appear to meet the basic requirements for habitability, but we now have an idea of how complex biomolecules might form there and what kind of chemical pathways might be involved.”
Water from the underground sea of Saturn’s moon Enceladus sprays into space from fissures, in a way that is somewhat reminiscent of geysers on Earth. The Cassini space probe, which took this photograph in 2010, captured samples of water ice particles while flying over one of these “geysers” on Enceladus, analyzed them, sent the data back to Earth, and scientists continue to make new discoveries from them. that valuable information. (Photo: NASA JPL / Caltech / Space Science Institute)
“The discovery of hydrogen cyanide has been especially exciting, because the compound is the starting point for most theories about the origin of life,” explains Peter. Life as we know it requires building blocks, such as amino acids, and hydrogen cyanide is one of the most important and versatile molecules needed to form amino acids. Because its molecules can be stacked in many different ways, the study authors refer to hydrogen cyanide as “the Swiss army knife of amino acid precursors.”
In 2017, scientists discovered signs of chemistry on Enceladus that could help support life, if it exists, in its ocean. The combination of carbon dioxide, methane and hydrogen in the plume suggested the existence of methanogenesis, a metabolic process that produces methane. Methanogenesis is widespread on Earth and could have been decisive for the emergence of life on our planet.
The new study reveals what appears to be a much more powerful and diverse source of chemical energy than that linked to methane production: the authors of the study have found a series of oxidized organic compounds, indicating that there are many chemical pathways to sustain potentially life in the underground ocean of Enceladus. This is because oxidation contributes to the release of chemical energy.
“If methanogenesis is like a small watch battery, in terms of energy, then our results suggest that Enceladus’ sea could host something more like a car battery, capable of providing a large amount of energy to any form of life. that could be present,” explains Kevin Hand, from NASA and co-author of the new study.
The Cassini-Huygens mission was a cooperation between NASA, ESA (European Space Agency) and the Italian Space Agency. (Source: NCYT from Amazings)
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