New organic compounds found in Enceladus ice grains

New organic compounds found in Enceladus ice grains
In this image captured by NASA's Cassini spacecraft in 2007, the plumes of Enceladus are clearly visible. The moon is nearly in front of the Sun from Cassini's viewpoint. Credit: NASA/JPL/Space Science Institute

New kinds of organic compounds, the ingredients of amino acids, have been detected in the plumes bursting from Saturn's moon Enceladus. The findings are the result of the ongoing deep dive into data from NASA's Cassini mission.

Powerful hydrothermal vents eject material from Enceladus' core, which mixes with water from the moon's massive subsurface ocean before it is released into space as water vapor and ice grains. The newly discovered molecules, condensed onto the ice grains, were determined to be nitrogen- and oxygen-bearing compounds.

On Earth, similar compounds are part of chemical reactions that produce , the building blocks of life. Hydrothermal vents on the provide the energy that fuels the reactions. Scientists believe Enceladus' may operate in the same way, supplying energy that leads to the production of amino acids.

"If the conditions are right, these molecules coming from the deep ocean of Enceladus could be on the same reaction pathway as we see here on Earth. We don't yet know if amino acids are needed for life beyond Earth, but finding the molecules that form amino acids is an important piece of the puzzle," said Nozair Khawaja, who led the research team of the Free University of Berlin. His findings were published Oct. 2 in the Monthly Notices of the Royal Astronomical Society.

Although the Cassini mission ended in September 2017, the data it provided will be mined for decades. Khawaja's team used data from the spacecraft's Cosmic Dust Analyzer, or CDA, which detected ice grains emitted from Enceladus into Saturn's E ring.

New organic compounds found in Enceladus ice grains
This illustration shows the process of organic compounds making their way onto ice grains emitted in plumes from Saturn's moon Enceladus, where they were detected by NASA's Cassini spacecraft. Credit: NASA/JPL-Caltech

The scientists used the CDA's mass spectrometer measurements to determine the composition of organic material in the grains.

The identified organics first dissolved in the ocean of Enceladus, then evaporated from the before condensing and freezing onto ice grains inside the fractures in the moon's crust, scientists found. Blown into space with the rising plume emitted through those fractures, the were then analyzed by Cassini's CDA.

The new findings complement the team's discovery last year of large, insoluble complex believed to float on the surface of Enceladus' ocean. The team went deeper with this recent work to find the ingredients, dissolved in the ocean, that are needed for the hydrothermal processes that would spur amino acid formation.

"Here we are finding smaller and soluble organic building blocks—potential precursors for amino acids and other ingredients required for life on Earth," said co-author Jon Hillier.

"This work shows that Enceladus' has reactive building blocks in abundance, and it's another green light in the investigation of the habitability of Enceladus," added co-author Frank Postberg.


Explore further

Scientists find evidence of complex organic molecules from Enceladus

More information: N Khawaja et al. Low-mass nitrogen-, oxygen-bearing, and aromatic compounds in Enceladean ice grains, Monthly Notices of the Royal Astronomical Society (2019). DOI: 10.1093/mnras/stz2280
Citation: New organic compounds found in Enceladus ice grains (2019, October 2) retrieved 20 October 2019 from https://phys.org/news/2019-10-compounds-enceladus-ice-grains.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
1144 shares

Feedback to editors

User comments

Oct 02, 2019
Powerful hydrothermal vents eject material from Enceladus' core, which mixes with water from the moon's massive subsurface ocean before it is released into space as water vapor and ice grains.

This is of course pure conjecture presented as fact. The water and other molecules are likely created by the electric discharge processes that are carving the "tiger stripes". Just as with Jupiter's Io, we already know of huge electric currents connecting Saturn and Enceladus. It's no coincidence these two moons are the most active moons in the solar system.

Oct 02, 2019
@cd
The water and other molecules are likely created by the electric discharge processes that are carving the "tiger stripes" blah blah blah
This is of course pure conjecture presented as fact

No references to peer-reviewed journal studies, no experiments, no scaling and no validation equals pseudoscience

Oct 02, 2019
Two things I noticed with curiosity/questioning. If I may quote two sentences; first, "then evaporated from the water surface before condensing and freezing", followed by, "insoluble complex organic molecules believed to float on the surface of Enceladus' ocean". So here is my question; is it believed there is actually a "surface" on Enceladus' ocean" from which things can "evaporate"? Much like the illustration accompanying the article, I'd always assumed the subsurface ocean extended from the floor to make direct contact with the ice comprising the surface crust. I realize much of what we know is still speculation, but what feature would constitute an ocean surface from which something might evaporate? Have I missed something?

Oct 03, 2019
Powerful hydrothermal vents eject material from Enceladus' core, which mixes with water from the moon's massive subsurface ocean before it is released into space as water vapor and ice grains.

This is of course pure conjecture presented as fact. The water and other molecules are likely created by the electric discharge processes that are carving the "tiger stripes". Just as with Jupiter's Io, we already know of huge electric currents connecting Saturn and Enceladus. It's no coincidence these two moons are the most active moons in the solar system.


Lol. More tales of woo from the wooists! I would say that you couldn't make this stuff up, but they obviously do!

Oct 03, 2019
That is nice! The ocean is now believed to be near neutral, so acidic vents should produce amino acids. The expected type of vent from the undifferentiated chondritic core is alkaline, serpentinization type, which would drive a cellular and metabolic like pH differential to an acidic flow.

On Earth the ocean was slightly acidic due to the early CO2 atmosphere. Local acidic flows would work too.

is it believed there is actually a "surface" on Enceladus' ocean" from which things can "evaporate"?


There are several surfaces involved. The water/ice interface surface, that would concentrate long chain fatty organics. And presumably vent crack surfaces, where the water and floating organics would evaporate from.

Oct 15, 2019
The original article misses out on the hype and lack of information in this press release and says that the compounds detected could be acetaldehyde or acetic acide and dimethyl amine or ethyl amine.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more