Enceladus

Laboratory Characterization Of Hydrothermally Processed Oligopeptides In Ice Grains Emitted By Enceladus And Europa

By Keith Cowing

Status Report

Philosophical Transactions Of The Royal Society A

June 25, 2024

Filed under biochemistry, biosignature, Cassini, dust, ejected ice grain, Enceladus, Europa, Europa Clipper, hydrothermal, hydrothermal processing, ice grain, impact ionization mass spectrometry, Mass Spectrometer, organic chemistry, Peptide, Philosophical Transactions Of The Royal Society A, spectrometry, SUrface Dust Analyzer (SUDA), triglycine

Laboratory Characterization Of Hydrothermally Processed Oligopeptides In Ice Grains Emitted By Enceladus And Europa — An artist’s rendition of Saturn’s moon Enceladus depicts hydrothermal activity on the seafloor and cracks in the moon’s icy crust that allow material from the watery interior to be ejected into space. New research shows that instruments destined for the next missions could find traces of a single cell in a single ice grain contained in a plume. NASA/JPL-Caltech

The Cassini mission provided evidence for a global subsurface ocean and ongoing hydrothermal activity on Enceladus, based on results from Cassini’s mass spectrometers. Laboratory simulations of hydrothermal conditions on icy moons are needed to further constrain the composition of ejected ice grains containing hydrothermally altered organic material.

Here, we present results from our newly established facility to simulate the processing of ocean material within the temperature range 80–150°C and the pressure range 80–130 bar, representing conditions suggested for the water–rock interface on Enceladus.

With this new facility, we investigate the hydrothermal processing of triglycine (GGG) peptide and, for the first time, analyse the extracted samples using laser-induced liquid beam ion desorption (LILBID) mass spectrometry, a laboratory analogue for impact ionization mass spectrometry of ice grains in space. We outline an approach to elucidate hydrothermally processed GGG in ice grains ejected from icy moons based on characteristic differences between GGG anion and cation mass spectra.

These differences are linked to hydrothermal processing and thus provide a fingerprint of hydrothermal activity on extraterrestrial bodies. These results will serve as important guidelines for biosignatures potentially obtained by a future Enceladus mission and the SUrface Dust Analyzer (SUDA) instrument onboard Europa Clipper.

Laboratory characterization of hydrothermally processed oligopeptides in ice grains emitted by Enceladus and Europa, Philosophical Transactions Of The Royal Society A

Astrobiology

Keith Cowing

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻

Follow on Twitter