Signs of life shooting from Saturn's moon Enceladus would be detectable by spacecraft, scientists say

Ice plumes shown shooting from Enceladus
This artistic rendering shows ice plumes being ejected from Enceladus at major speeds. (Image credit: NASA)

When NASA's Cassini spacecraft turned its instruments to Saturn's moon Enceladus, it observed plumes of ice shooting up from the moon's surface at speeds of about 900 miles per hour (1,448 kilometers per hour). These geysers seemed to be the tendrils of a vast subsurface ocean — and made scientists curious if their fluid might carry life signs, organic molecules.

But if scientists want to study those organic molecules, they'll need to find a careful way of collecting them without destroying them. There is now good news on that front: If one lab experiment is correct, then any possible amino acids in those geysers' fluid are expected to  easily survive contact with a spacecraft.

Researchers learned this in the lab by working with a physical apparatus designed to examine collisions. The researchers created ice particles by pushing water through a high-voltage needle; the charge fragmented the water into tiny droplets, each of which crystallized into an ice grain as it entered a vacuum. Then, the researchers shot the hardened grains through a spectrometer and imaged each grain as well as recorded impact times. 

They found that amino acids within the ice grains could survive impact speeds up to 9,400 mph (15,128 kilometers per hour). That's more than enough to survive an encounter with a space probe.

Related: Saturn's moon Enceladus has all the ingredients for life in its icy oceans. But is life there?

To determine if ice contains fingerprints of life, scientists want to get undamaged ice grains so they can get a clear read on compounds that lie within the ice. "Our work shows that this is possible with the ice plumes of Enceladus," Robert Continetti, a chemist at the University of California San Diego and one of the researchers behind the work, said in a statement

And while the experiment used data from Enceladus, it has consequences beyond one moon of Saturn. If similar amino acids exist on other water-bearing moons, like Jupiter's Europa, then missions like the future Europa Clipper might be able to find them in ice grains as well.

The researchers published their work on Dec. 4 in the journal Proceedings of the National Academy of Sciences.

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Rahul Rao
Contributing Writer

Rahul Rao is a graduate of New York University's SHERP and a freelance science writer, regularly covering physics, space, and infrastructure. His work has appeared in Gizmodo, Popular Science, Inverse, IEEE Spectrum, and Continuum. He enjoys riding trains for fun, and he has seen every surviving episode of Doctor Who. He holds a masters degree in science writing from New York University's Science, Health and Environmental Reporting Program (SHERP) and earned a bachelors degree from Vanderbilt University, where he studied English and physics. 

  • rod
    Interesting experiment and test. I note from the paper cited.

    Detection of intact amino acids with a hypervelocity ice grain impact mass spectrometer,, "...The results reported here provide unambiguous laboratory evidence that we could fly through these plumes at speeds up to 4.2 km/s and successfully detect intact amino acids, an important class of biosignature molecules, in situ with a mass spectrometer." "Abstract Astrobiology studies are a top priority in answering one of the most fundamental questions in planetary science: Is there life beyond Earth? Saturn’s icy moon Enceladus is a prime target in the search for life in our solar system, identified by NASA as the second-highest priority site for a flagship mission in the next decade..."

    Potential future detections of amino acids at Enceladus is one thing, showing how non-living matter evolved into life at Enceladus is another. features many reports on abiogenesis in astrobiology it seems and even perhaps taking place in gas clouds in space now too.
  • jamestmallow
    rod said:
    rod said:
    "Potential future detections of amino acids at Enceladus is one thing, showing how non-living matter evolved into life at Enceladus is another."
    You seem to be dismissing what would be one of the greatest discoveries of all time - life outside of Earth. That would be more than "one thing." It would be awesome. The next step would be to determine if it came from a separate (or the same) abiogenesis event as Earth life.
  • rod
    Interesting thinking in post #3. Charles Darwin wanted to see non-living matter evolve into life in his 1871 letter, nothing at that time and in his 1882 letter, nothing worthwhile either for abiogenesis. Showing that Enceladus has life on it today or abiogenesis took place on Enceladus in the past - remains to be confirmed. I remember well Bill Clinton press conference during his administration for meteorite ALH84001. Tiny Martian life claimed or thought. If it is ever accepted in science that Earth is the only place in the galaxy where life exists with plants, trees, etc. thrive, that is very awesome too. At the moment, it seems many are waiting for the check is in the mail here :)
  • Torbjorn Larsson"NASA Study Finds Life-Sparking Energy Source and Molecule at Enceladus"

    They have found NH3 - a nitrogen source - before, and with an ice cover the increased redox span of dissimilar products was expected (if welcome). Personally I found their “Moderate” support for H2S – supporting the alkaline hydrothermal vent source hypothesis – and PH3 – a phosphorous source – most exciting!
  • Torbjorn Larsson
    rod said:
    Potential future detections of amino acids at Enceladus is one thing, showing how non-living matter evolved into life at Enceladus is another.
    If it did, precisely in the way that modern phylogenetic methods show how biology split from geology: in alkaline hydrothermal vent formations at the deep ocean floor.

    Since the evolution from non life geology over half alive cells to the LUCA was so rapid and the process diversifies so easily, it is likely an easy process too.