Using data from NASA’s Cassini mission, planetary scientists have detected several compounds critical to the habitability of Saturn’s icy moon Enceladus, including hydrogen cyanide, acetylene, propylene, and ethane. . These compounds may support living microbial communities or drive complex organic syntheses leading to the origin of life.

“Our study provides further evidence that Enceladus hosts some of the most important molecules for both producing the building blocks of life and sustaining life through metabolic reactions,” said Harvard University Ph.D. said Jonah Peter, a student in the program.

“Not only does Enceladus appear to meet the basic requirements for habitability, but we are also wondering how complex biomolecules are formed there and what kinds of chemical pathways are involved. I got an idea about it.”

“The discovery of hydrogen cyanide was particularly exciting because it is the starting point for most theories about the origin of life.”

As we know, life requires building blocks such as amino acids, and hydrogen cyanide is one of the most important and versatile molecules required for the formation of amino acids.

Peter and his colleagues refer to hydrogen cyanide as the Swiss Army knife of amino acid precursors because its molecules stack up in different ways.

“The more we tested alternative models and tried to poke holes in the results, the stronger the evidence became,” Peter said.

“Ultimately, it became clear that there was no way to match the plume composition without including hydrogen cyanide.”

Saturn’s moon Enceladus with plumes. Image credit: NASA / JPL-Caltech / SSI / Kevin M. Gill.

In 2017, planetary scientists discovered evidence of chemistry on Enceladus that could help sustain life in the ocean, if it exists.

The combination of carbon dioxide, methane, and hydrogen in the plume suggested methanogenesis, a metabolic process that produces methane.

This process is widespread on Earth and may have been important for the origin of life on Earth.

Peter and his co-authors found evidence for additional energetic chemical sources that are far more powerful and diverse than methane production.

They discovered a series of oxidized organic compounds, showing scientists that Enceladus’ underground ocean potentially has many chemical pathways to support life. That’s because oxidation promotes the release of chemical energy.

“If methane production is like a small clock battery in terms of energy, then our findings suggest that Enceladus’ ocean could provide large amounts of energy for any life that might exist. This suggests that we may be able to provide something similar to car batteries,” said Dr. Kevin Hand, a researcher at NASA’s Jet Propulsion Laboratory.

Unlike previous studies that used laboratory experiments and geochemical modeling to recreate the conditions Cassini found on Enceladus, the authors relied on detailed statistical analysis.

They examined data collected by Cassini’s ion and neutral mass spectrometers, which study the gas, ions, and ice grains around Saturn.

By quantifying the amount of information contained in the data, the authors were able to uncover subtle differences in how well different compounds explain the Cassini signal.

“There are a lot of potential puzzle pieces that can be put together when trying to reconcile observed data,” Peter said.

“We used mathematics and statistical modeling to identify the combination of puzzle pieces that best matched the plume’s composition and made the most of the data without over-interpreting the limited data set.”

of findings It was published in the magazine natural astronomy.

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JS Peter other. Detection of HCN and diverse redox chemistries in Enceladus plumes. Nat Astron, published online on December 14, 2023. doi: 10.1038/s41550-023-02160-0