Stability of nucleic acid bases in concentrated sulfuric acid: Implications for the habitability of Venus’ clouds

Proceedings of the National Academy of Sciences, Год журнала: 2023, Номер 120(25)

Опубликована: Июнь 12, 2023

What constitutes a habitable planet is frontier to be explored and requires pushing the boundaries of our terracentric viewpoint for what we deem environment. Despite Venus' 700 K surface temperature being too hot any plausible solvent most organic covalent chemistry, cloud-filled atmosphere layers at 48 60 km above hold main requirements life: suitable temperatures bonds; an energy source (sunlight); liquid solvent. Yet, Venus clouds are widely thought incapable supporting life because droplets composed concentrated sulfuric acid-an aggressive that assumed rapidly destroy biochemicals on Earth. Recent work, however, demonstrates rich chemistry can evolve from simple precursor molecules seeded into acid, result corroborated by domain knowledge in industry such leads complex molecules, including aromatics. We aim expand set known stable acid. Here, show nucleic acid bases adenine, cytosine, guanine, thymine, uracil, as well 2,6-diaminopurine "core" purine pyrimidine, cloud concentration range, using UV spectroscopy combinations 1D 2D

Язык: Английский

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Stability of 20 Biogenic Amino Acids in Concentrated Sulfuric Acid: Implications for the Habitability of Venus' Clouds

Astrobiology, Год журнала: 2024, Номер 24(4), С. 386 - 396

Опубликована: Март 18, 2024

Scientists have long speculated about the potential habitability of Venus, not at 700K surface, but in cloud layers located 48–60 km altitudes, where temperatures match those found on Earth's surface. However, prevailing belief has been that Venus' clouds cannot support life due to chemical composition concentrated sulfuric acid—a highly aggressive solvent. In this work, we study 20 biogenic amino acids range acid concentrations (81% and 98% w/w, rest water) temperatures. We find 19 tested are either unreactive (13 w/w 12 81% w/w) or chemically modified side chain only, after 4 weeks. Our major finding, therefore, is backbone remains intact acid. These findings significantly broaden biologically relevant molecules could be components a biochemistry based

Язык: Английский

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Venus Life Finder Missions Motivation and Summary

Aerospace, Год журнала: 2022, Номер 9(7), С. 385 - 385

Опубликована: Июль 18, 2022

Finding evidence of extraterrestrial life would be one the most profound scientific discoveries ever made, advancing humanity into a new epoch cosmic awareness. The Venus Life Finder (VLF) missions feature series three direct atmospheric probes designed to assess habitability Venusian clouds and search for signs itself. VLF are an astrobiology-focused set missions, first two out can launched quickly at relatively low cost. mission concepts come 18-month study by MIT-led worldwide consortium.

Язык: Английский

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Tracing the inner edge of the habitable zone with sulfur chemistry

Science Advances, Год журнала: 2025, Номер 11(5)

Опубликована: Янв. 29, 2025

The circumstellar liquid-water habitable zone guides our search for potentially inhabited exoplanets but remains observationally untested. We show that the inner edge of can now be mapped among using their lack surface water, which, unlike presence unambiguously revealed by atmospheric sulfur species. Using coupled climate-chemistry modeling, we find observability gases on depends critically ultraviolet (UV) flux host star, a property with wide variation: Most M-dwarfs have low UV and thereby allow detection as tracer dry planetary surfaces; however, Trappist-1 may too high to disambiguate uninhabitable from surfaces any its planets. generalize this result how population-level chemistry M-dwarf planets used empirically define in near future.

Язык: Английский

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Simple Lipids Form Stable Higher-Order Structures in Concentrated Sulfuric Acid

Astrobiology, Год журнала: 2025, Номер unknown

Опубликована: Март 26, 2025

Venus has become a target of astrobiological interest because it is physically accessible to direct exploration, unlike exoplanets. So far this been motivated not by the explicit expectation finding life but rather desire understand limits biology. The venusian surface sterilizing, cloud deck includes regions with temperatures and pressures conventionally considered compatible life. However, clouds are thought consist concentrated sulfuric acid. To determine if any fundamental features as we them here on Earth could in principle exist these extreme solvent conditions, tested several simple lipids for resistance solvolysis their ability form structures We find that single-chain saturated sulfate, alcohol, trimethylamine, phosphonate head groups resistant acid degradation at room temperature. Furthermore, they stable higher-order typically associated lipid membranes, micelles, vesicles. Finally, results from molecular dynamics simulations suggest explanation observed robustness formed conclude implications study experimental astrobiology.

Язык: Английский

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Low levels of sulphur dioxide contamination of Venusian phosphine spectra

Monthly Notices of the Royal Astronomical Society, Год журнала: 2022, Номер 514(2), С. 2994 - 3001

Опубликована: Май 30, 2022

ABSTRACT New analysis is presented of the 1.1 mm wavelength absorption lines in Venus’ atmosphere that suggested presence phosphine. We retrieve a sulphur dioxide observation from JCMT archive was simultaneous within few days PH3 1-0 spectrum obtained 2017 June, and demonstrate via radiative transfer calculation contamination by SO2 ≈10 per cent. also present ALMA 2019 spectra an transition acquired simultaneously, infer line-contamination ≲2 cent (for least-noisy half planetary disc). The contamination-subtracted (of 6–8σ sigma confidence) are now consistent with similar absorption-depths at two epochs. values span −1.9(±0.2) 10−4 continuum signal (which re-estimated for ALMA), albeit differing areas. This suggests abundance attributed to phosphine broadly 2019.

Язык: Английский

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Venus' Atmospheric Chemistry and Cloud Characteristics Are Compatible with Venusian Life

Astrobiology, Год журнала: 2023, Номер 24(4), С. 371 - 385

Опубликована: Июнь 12, 2023

Venus is Earth's sister planet, with similar mass and density but an uninhabitably hot surface, atmosphere a water activity 50-100 times lower than anywhere on Earths' clouds believed to be made of concentrated sulfuric acid. These features have been taken imply that the chances finding life are vanishingly small, several authors describing Venus' as "uninhabitable", apparent signs there must therefore abiotic, or artefactual. In this article, we argue although many can rule out possibility Earth could live there, none all based what know physical principle Earth. Specifically, abundant energy, energy requirements for retaining capturing hydrogen atoms build biomass not excessive, defenses against acid conceivable terrestrial precedent, speculative uses solvent instead remains. Metals likely available in limited supply, radiation environment benign. The support readily detectable by future astrobiology-focused space missions from its impact atmosphere. Although consider prospects speculative, they absent. scientific reward such un-Earthlike justifies considering how observations should designed capable detecting if it there.

Язык: Английский

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Atmospheric carbon depletion as a tracer of water oceans and biomass on temperate terrestrial exoplanets

Nature Astronomy, Год журнала: 2023, Номер 8(1), С. 17 - 29

Опубликована: Дек. 28, 2023

Язык: Английский

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General instability of dipeptides in concentrated sulfuric acid as relevant for the Venus cloud habitability

Scientific Reports, Год журнала: 2024, Номер 14(1)

Опубликована: Июль 24, 2024

Recent renewed interest in the possibility of life acidic clouds Venus has led to new studies on organic chemistry concentrated sulfuric acid. We have previously found that majority amino acids are stable range Venus' cloud acid concentrations (81% and 98% w/w, rest being water). The natural next question is whether dipeptides, as precursors larger peptides proteins, could be this environment. investigated reactivity peptide bond using 20 homodipeptides find them undergo solvolysis within a few weeks, at both concentrations. Notably, exceptions exist. HH GG dipeptides w/w for least 4 months, while II, LL, VV, PP, RR KK resist hydrolysis 81% 5 weeks. Moreover, breakdown process studied different from standard acid-catalyzed releases monomeric acids. Despite single concentration, no demonstrated stability across studied. This indicates any hypothetical would likely require functional substitute can maintain throughout present.

Язык: Английский

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Alternative Solvents for Life: Framework for Evaluation, Current Status, and Future Research

Astrobiology, Год журнала: 2024, Номер unknown

Опубликована: Дек. 2, 2024

Life is a complex, dynamic chemical system that requires dense fluid solvent in which to take place. A common assumption the most likely for life liquid water, and some researchers argue water only plausible solvent. However, persistent theme astrobiological research postulates other liquids might be cosmically could solvents chemistry of life. In this article, we present new framework analysis candidate life, deploy review substances have been suggested as candidates. We categorize each through following four criteria: occurrence, solvation, solute stability, functionality. Our semiquantitative approach addresses all requirements not from point view its properties but also standpoint biochemical function. Only protonating fulfill those concentrated sulfuric acid are abundant rocky planetary context. Among nonprotonating solvents, CO

Язык: Английский

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