Effects of UV-organic interaction and martian conditions on the survivability of organics

Laurent, Boris; Cousins, C. R.; Pereira, M.F.C.; Martins, Zita

doi:10.1016/j.icarus.2019.01.020

Cited by 9 publications

(7 citation statements)

References 56 publications

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“…It focuses on the concentration of organic matter at the surface of Mars according to the regolith depth, latitude, longitude, and seasons. For example, the latitudinal variation of the relative UV environment will modify degradation rate of organic matter as it depends on the quantity of photons interacting with the organic molecules (Laurent et al, 2019). The goal of this model is to predict which compounds at what level could be detected on Mars by in situ mission, and what their origin (biotic versus abiotic) might be.…”

Section: Discussionmentioning

confidence: 99%

The Photochemistry on Space Station (PSS) Experiment: Organic Matter under Mars-like Surface UV Radiation Conditions in Low Earth Orbit

et al. 2019

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The search for organic molecules at the surface of Mars is a top priority of the Mars Science Laboratory (NASA) and ExoMars 2020 (ESA) space missions. Their main goal is to search for past and/or present molecular compounds related to a potential prebiotic chemistry and/or a biological activity on the Red Planet. A key step to interpret their data is to characterize the preservation or the evolution of organic matter in the martian environmental conditions. Several laboratory experiments have been developed especially concerning the influence of ultraviolet (UV) radiation. However, the experimental UV sources do not perfectly reproduce the solar UV radiation reaching the surface of Mars. For this reason, the International Space Station (ISS) can be advantageously used to expose the same samples studied in the laboratory to UV radiation representative of martian conditions. Those laboratory simulations can be completed by experiments in low Earth orbit (LEO) outside the ISS. Our study was part of the Photochemistry on the Space Station experiment on board the EXPOSE-R2 facility that was kept outside the ISS from October 2014 to February 2016. Chrysene, adenine, and glycine, pure or deposited on an iron-rich amorphous mineral phase, were exposed to solar UV. The total duration of exposure to UV radiation is estimated to be in the 1250-1420 h range. Each sample was characterized prior to and after the flight by Fourier transform infrared (FTIR) spectroscopy. These measurements showed that all exposed samples were partially degraded. Their quantum efficiencies of photodecomposition were calculated in the 200-250 nm wavelength range. They range from 10-4 to 10-6 molecules$photon-1 for pure organic samples and from 10-2 to 10-5 molecules$photon-1 for organic samples shielded by the mineral phase. These results highlight that none of the tested organics are stable under LEO solar UV radiation conditions. The presence of an iron-rich mineral phase increases their degradation.

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Section: Discussionmentioning

confidence: 99%

The Photochemistry on Space Station (PSS) Experiment: Organic Matter under Mars-like Surface UV Radiation Conditions in Low Earth Orbit

et al. 2019

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“…The use of natural volcanic dust as an analogue of martian terrains , is an additional opportunity to work with dusts representative of the surface of Mars in the laboratory. Recent works have been carried out to improve our knowledge of the mineral phase of martian regolith analogues, and of the interaction between the mineral matrices and biomarkers. − …”

Section: Heterogeneous Reactivity In the Atmosphere Of Marsmentioning

confidence: 99%

Heterogeneous Physical Chemistry in the Atmospheres of Earth, Mars, and Venus: Perspectives for Rocky Exoplanets

Lasne¹

2021

ACS Earth Space Chem.

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With recent progress of observational astronomy, the next generation of space telescopes (JWST, ARIEL, OST, HabEx, LUVOIR) will be able to determine the composition of exoplanetary atmospheres in the next decades. The discovery of rocky exoplanets, as potentially favorable harbors for life, finds a particularly strong echo in the scientific community and in the general audience. The interaction of the surface of a planetary body with its atmosphere is key to understanding the composition of the latter and hence to determine whether the planet may host life or not. In an effort to describe surface–atmosphere interactions on rocky planets and the heterogeneous reactions occurring on solid surfaces, in particular mineral dust grains, in such systems it is necessary to develop a systematic approach to this family of reactions. Such an approach is proposed in this Perspective on three very distinct examples of rocky planets: Earth, Mars, and Venus. These bodies have experienced very different evolutions, although they likely started from similar initial conditions; the pressure and temperature of their atmospheres cover a broad range of values, offering an invaluable set of planet-size laboratories to study the impact of physical and chemical parameters on the evolution of atmospheres. Systems that should be investigated in priority with relevance for Earth, Mars, and Venus are discussed. It is shown that a better knowledge of mineral dust supporting heterogeneous reactivity is crucial and that the impact of environmental parameters on these reactions needs to be carefully investigated. Current and future missions to Mars and Venus will require such work to better model and understand the observations. In particular, a strong effort is needed to study Venus, which has only few dedicated laboratory setups although it will be the target of exploration missions in the next decades. These studies will pave the way to build robust models of exoplanetary atmospheres, which will be crucial to account for the observations of their composition by space telescopes in the near future.

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“…While the UV photons are limited in the upper layer of Martian sub-surface, as they are absorbed by rocks [ 9 , 11 ], GCRs have the capability to penetrate to 1–2 m in the sub-surface in spite of chemical and physics features of rocks or ice content [ 9 ]. Besides, UV flux depends on function of latitude and some molecular targets (e.g., amino acids) could be easily destroyed when embedded in highly UV-penetrated materials [ 12 ].…”

Section: Introductionmentioning

confidence: 99%

Insights into the Survival Capabilities of Cryomyces antarcticus Hydrated Colonies after Exposure to Fe Particle Radiation

Pacelli

Cassaro

Siong

et al. 2021

JoF

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The modern concept of the evolution of Mars assumes that life could potentially have originated on the planet Mars, possibly during the end of the late heavy bombardment, and could then be transferred to other planets. Since then, physical and chemical conditions on Mars changed and now strongly limit the presence of terrestrial-like life forms. These adverse conditions include scarcity of liquid water (although brine solutions may exist), low temperature and atmospheric pressure, and cosmic radiation. Ionizing radiation is very important among these life-constraining factors because it damages DNA and other cellular components, particularly in liquid conditions where radiation-induced reactive oxidants diffuse freely. Here, we investigated the impact of high doses (up to 2 kGy) of densely-ionizing (197.6 keV/µm), space-relevant iron ions (corresponding on the irradiation that reach the uppermost layer of the Mars subsurface) on the survival of an extremophilic terrestrial organism—Cryomyces antarcticus—in liquid medium and under atmospheric conditions, through different techniques. Results showed that it survived in a metabolically active state when subjected to high doses of Fe ions and was able to repair eventual DNA damages. It implies that some terrestrial life forms can withstand prolonged exposure to space-relevant ion radiation.

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Effects of UV-organic interaction and martian conditions on the survivability of organics

Cited by 9 publications

References 56 publications

The Photochemistry on Space Station (PSS) Experiment: Organic Matter under Mars-like Surface UV Radiation Conditions in Low Earth Orbit

The Photochemistry on Space Station (PSS) Experiment: Organic Matter under Mars-like Surface UV Radiation Conditions in Low Earth Orbit

Heterogeneous Physical Chemistry in the Atmospheres of Earth, Mars, and Venus: Perspectives for Rocky Exoplanets

Insights into the Survival Capabilities of Cryomyces antarcticus Hydrated Colonies after Exposure to Fe Particle Radiation

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