Print button

Abstract EANA2025-14


Dragonfly may be able to sample amino acids produced on the polar cryovolcanic regions of Titan

Diogo Gonçalves (1,2), Florence Hofmann (3), Severin Wipf (3), Riccardo G. Urso (4), Jana Bocková (5), Cornelia Meinert (5), Paul B. Rimmer (6), Gautam D. Stroscio (7), Nir Goldman (7,8), Andreas Elsaesser (3), Bruno Pedras (2), and Zita Martins (1)
(1) Centro de Química Estrutural – Institute of Molecular Sciences – and Department of Chemical Engineering, Instituto Superior Técnico, Universidade de Lisboa, Portugal, (2) Institute for Bioengineering and Biosciences – Associate Laboratory Institute for Health and Bioeconomy – and Department of Chemical Engineering, Instituto Superior Técnico, Universidade de Lisboa, Portugal, (3) Freie Universität Berlin, Department of Physics, Arnimallee 14, 14195 Berlin, Germany, (4) INAF-Osservatorio Astrofisico di Catania, Via Santa Sofia 78, 95123 Catania, Italy, (5) Université Côte d'Azur-CNRS, ICN, UMR7272, 06108 Nice, France, (6) Cavendish Laboratory, University of Cambridge, JJ Thomson Ave, CB3 0HE Cambridge, UK, (7) Lawrence Livermore National Laboratory, Livermore, California 94550, United States, (8) Department of Chemical Engineering, University of California, Davis, California 95616, United States


The impact craters and cryovolcanic regions of Titan may currently preserve the products of the hydrolysis of its atmospheric organic macromolecules. The hydrolysis products likely include several prebiotic molecules [1,2]. The extent of such prebiotic chemistry on Titan’s surface will be explored by NASA’s Dragonfly mission [3]. By landing on equatorial locations, it may not, however, sample cryovolcanic regions (most common on the poles [4]) and their extensively demonstrated prebiotic potential [5]. To mitigate that missed opportunity, we devised a two-step scenario through which prebiotic molecules produced in the polar cryovolcanic regions could be sampled, by Dragonfly, in the equator. We suggest that the exsolution of gases from the cryolavas should encapsulate the prebiotic molecules in water-ammonia icy aerosols [6]; afterwards, Titan’s Hadley circulation may transport them from the summer pole to the equator. Icy aerosols bearing prebiotic molecules would thus accumulate in the equator, likely within its organic dunes, prone to be sampled by Dragonfly. Concerningly, the pole-to-equator branch of the Hadley circulation sits at mesospheric altitudes, in which the prebiotic molecules would be subject to energetic solar irradiation. We investigated whether the irradiation felt in Titan’s mesosphere photodegrades glycine and alanine at a rate that hinders their pole-to-equator journey. We evaluated their photodegradation by adapting an experimental concept [7] previously explored to study the photochemistry of organic molecules in space and planetary conditions [8,9]. Comparing the calculated half-lives on Titan’s mesosphere to the expected transportation timescale, we conclude that the two amino acids can survive the proposed pole-to-equator transportation. We suggest that Dragonfly may indeed find prebiotic molecules produced in the polar cryovolcanic regions [10]. Also, our results indicate that the solid-state interaction between alanine and glycine [11] increased the photodegradation rate of the latter by ten times [10]. We justify this from changes in the environment polarity [10].

Acknowledgments

The authors acknowledge funding by Fundação para a Ciência e Tecnologia (UIDB/00100/2020, UIDP/00100/2020,  LA/P/0056/ 2020, UIDB/04565/2020, UIDP/04565/2020, LA/P/ 0140/2020, and 2021.04932.BD), the Ministry of Economics and Energy, Germany (50WB2023 and 50WB2323), the Einstein Foundation Berlin (IPF-2018-469), the Volkswagen Foundation (Freigeist Program), INAF (RSN3 “ORSO” C63C23001250005), the U.S. Department of Energy (DE-AC52-07NA27344), and the European Research Council (804144, ERC-ALIFE).

References

[1] C. Brassé, et al., Astrobiology 2017, 17, 8–26.

[2] F. Raulin, et al., Chem Soc Rev 2012, 41, 5380–5393.

[3] J. W. Barnes, et al., Planet Sci J 2021, 2, 130.

[4] K. K. Farnsworth, et al., ACS Earth Space Chem 2024, 8, 2380–2392.

[5] C. A. Wood, J. Radebaugh, J Geophys Res Planets 2020, 125, e2019JE006036.

[6] D. Cordier, et al., J Geophys Res Planets 2024, 129, e2023JE008248.

[7] F. Hofmann, et al., Earth Planets Space 2025, 77, 1–13.

[8] V. J. Herrero, et al., Mon Not R Astron Soc 2022, 517, 1058–1070.

[9] O. Poch, et al., Planet Space Sci 2013, 85, 188–197.

[10] D. Gonçalves, et al., ACS Earth Space Chem 2025, 9, 715–728.

[11] D. Gonçalves, et al., ACS Earth Space Chem 2025, 9, 356–368.