Unveiling the Secrets of Saturn’s Moon: Discovery of Amino Acids in Enceladus’ Ice Plumes

A significant scientific discovery has uncovered that amino acids within the ice plumes of Saturn’s moon, Enceladus, are capable of withstanding high-speed impacts. This finding bolsters the possibility of extraterrestrial life. Source: SciTechPost.com

The ice plumes of Enceladus may be a source of life’s essential components.

The evolution of astrophysics technology and research continually raises the question: does life exist elsewhere in the universe? The Milky Way alone is home to countless celestial entities. In their quest for extraterrestrial life, scientists focus on three essential elements: water, energy, and organic substances. Saturn’s moon Enceladus, classified as an ‘ocean world,’ possesses these critical components, positioning it as a key candidate in the quest for life.

Discoveries of Cassini at Enceladus

NASA’s Cassini spacecraft, during its two-decade-long mission, identified that Enceladus ejects ice plumes at speeds up to 800 miles per hour (400 m/s). These plumes are ideal for sampling, offering insights into the moon’s ocean composition and habitability potential. Previously, it was uncertain whether the plumes’ velocity would disrupt organic compounds in the ice grains, potentially compromising the samples.

(Artistic illustration of Enceladus ejecting ice plumes at velocities reaching 800 miles/hour. Credit: NASA/JPL-Caltech)

Advancements in Laboratory Investigations

Researchers from the University of California San Diego have now provided clear laboratory evidence that amino acids in these ice plumes can endure impacts at speeds up to 4.2 km/s. This supports their identification during spacecraft sampling. Their research is published in The Proceedings of the National Academy of Sciences (PNAS).

Innovative Aerosol Impact Spectrometer

Beginning in 2012, UC San Diego’s Distinguished Professor of Chemistry and Biochemistry Robert Continetti and his team developed a unique aerosol impact spectrometer. This device, designed for studying the high-velocity collision dynamics of single aerosols and particles, turned out to be perfect for examining ice grain impacts.

“This device is globally unique in its ability to select individual particles and adjust their speeds to predetermined velocities,” Continetti explained. “It allows us to investigate particle behaviors like scattering or structural changes upon impact, for particles ranging from several microns to hundreds of nanometers, across various materials.”

Europa Clipper Mission

NASA’s planned 2024 launch of the Europa Clipper to Jupiter’s moon Europa, another oceanic world similar to Enceladus, holds promise. The mission aims to identify specific molecules in ice grains that could indicate life in the moons’ subsurface oceans. However, these molecules must remain intact after their high-speed ejection and subsequent collection by probes.

(Illustration of NASA’s Europa Clipper spacecraft. Credit: NASA/JPL-Caltech)

Revolutionary Experimental Methods

Continetti’s team is pioneering in measuring the outcomes when a single ice grain impacts a surface. The experiment involved generating ice grains through electrospray ionization, where water is propelled through a high-voltage needle, creating charged droplets that subsequently freeze in a vacuum. The team recorded the mass and charge of the grains, then used image charge detectors to track them through the spectrometer. A critical aspect of the experiment was installing a microchannel plate ion detector to precisely time the impact.

Astrobiological Significance

The study demonstrated that amino acids, fundamental to life, can be detected with minimal fragmentation at impact speeds up to 4.2 km/s.

“To understand potential life forms in the solar system, it’s vital to know that the molecular integrity of sampled ice grains is maintained, allowing us to identify life’s unique markers,” Continetti remarked. “Our findings affirm this is feasible with Enceladus’ ice plumes.”

Implications for Chemistry

This research also opens new inquiries in chemistry, particularly how salt influences amino acid detectability. Enceladus is believed to harbor vast salty oceans, surpassing Earth’s. Salt alters water’s solvent properties and molecule solubility, possibly causing some molecules to accumulate on ice grain surfaces, increasing detection likelihood.

“Our findings not only have profound implications for discovering life in other parts of the solar system without surface missions but also extend to basic chemical research,” Continetti stated. “We are excited to build upon the foundational work of Harold Urey and Stanley Miller at UC San Diego, exploring the formation of life’s building blocks through chemical reactions triggered by ice grain impact.”

Reference: “Detection of intact amino acids with a hypervelocity ice grain impact mass spectrometer” by Sally E. Burke, Zachary A. Auvil, Karl A. Hanold, and Robert E. Continetti, 4 December 2023, Proceedings of the National Academy of Sciences.
DOI: 10.1073/pnas.2313447120

This research was

Frequently Asked Questions (FAQs) about Enceladus Amino Acids

More about Enceladus Amino Acids

• Saturn’s Moon Enceladus and Amino Acids
• NASA’s Cassini Mission Discoveries
• UC San Diego’s Research on Enceladus
• Europa Clipper Mission Overview
• Proceedings of the National Academy of Sciences (PNAS) Study
• Astrobiology and Extraterrestrial Life Research