Abstract_EANA2025-97

Abstract EANA2025-97

Detecting cellular biosignatures from Sphingopyxis alaskensis under simulated Enceladus surface conditions

Mirandah Ackley (1), Marie Dannenmann (1), Alvaro Del Moral Jimenez (2), Karen Olsson-Francis (2), Zoe Emerland (3), Matthew Sylvest (3), Frank Postberg (1), Manish Patel (3)

(1) Planetary Sciences and Remote Sensing Group, Institute of Geological Sciences, Freie Universität Berlin, Berlin, Germany (2) AstrobiologyOU, Faculty of Science, Technology, Engineering & Mathematics, The Open University, Milton Keynes, UK (3) Hypervelocity Impact Laboratory, School of Physical Sciences, The Open University, Milton Keynes, UK

Ocean-bearing icy moons, such as Saturn’s moon Enceladus, are considered prime targets in the search for extraterrestrial life in the Solar System (Cable et al., 2021; Mousis et al., 2022). Mass spectrometry analysis of ice grains from Enceladus have already identified a variety of organic material originating from the moon’s cryovolcanic plume using impact ionization mass spectrometry, as demonstrated by the Cassini-Huygens mission (Postberg, et al., 2018; Khawaja et al., 2019) The Planetary Sciences group at Freie Universität Berlin is specialized in simulating mass spectra obtained from ice grains in space by a laser-induced-liquid-beam-ion-desorption mass spectrometer (LILBID-MS) (Klenner et al., 2019). Preliminary experiments using simulated ice grains have accurately identified biomolecules such as amino acids, peptides, sugars, and fatty acids from within cells (Dannenmann et al., 2023), while distinguishing between molecular patterns with biotic or abiotic origins (Klenner et al., 2020) with a modern space borne ice grain analyser like SUDA. Furthermore, it has been demonstrated that cell material from within a single ice grain emitted from Enceladus or Europa can be identified (Klenner et al., 2024). However, there are still gaps in our knowledge on how these detectable cellular biosignatures may be altered by a harsh environment such as the surface of Enceladus or inside its plume, with its low temperatures, vacuum, and high levels of attenuated solar UV radiation.

This work investigates how extreme environmental conditions that are characteristic of Enceladus' surface or its plume may affect the mass spectral biosignatures of model organism Sphingopyxis alaskensis. Using a planetary surface simulation chamber at The Open University, UK, we subject the microorganisms to conditions relevant to the surface of Enceladus: 173 K, 5 milibar, and UV doses equivalent to up to 2 days on Enceladus’ surface. The mass spectra of the microorganisms will then be measured using the LILBID-MS laboratory setup to determine whether detectable biosignatures have been altered, and how.

Understanding how planetary surface conditions affect the way cell material is presented in mass spectral data is conducive to the identification of organic biosignatures in future spaceflight missions. This research will advance our understanding of how potential cellular biosignatures might be altered by extreme conditions, directly informing biosignature detection strategies for future planetary exploration missions.

[1] M. L. Cable et al. The Planetary Science Journal, 2(4), 132 (2021)

[2] O. Mousis et al. The Planetary Science Journal, 3(12):268 (2022)

[3] F. Postberg, et al. Nature, 558(7711), 564-568 (2018)

[4] N. Khawaja et al. Monthly Notices of the Royal Astronomical Society, 489(4), 5231-5243 (2019)

[5] F. Klenner et al. Rapid Communications in Mass Spectrometry, 33(22), 1751–1760 (2019)

[6] M. Dannenmann et al. Astrobiology, 23(1), 60-75 (2023)

[7] F. Klenner et al. Astrobiology, 20(2), 179-189 (2020)

[8] F. Klenner & J. Bönigk et al. Science Advances, 10(12) (2024)