Venus, phosphine and the possibility of life

Contemporary Physics, Год журнала: 2022, Номер 63(3), С. 180 - 199

Опубликована: Июль 3, 2022

The search for life elsewhere in the universe is one of central aims science twent-first century. While most this work aimed at planets orbiting other stars, our own Solar System an important part endeavour. Venus often thought to have too harsh environment life, but it may been a more hospitable place distant past. If evolved there past then cloud decks are only remaining niche where as we know might survive today. discovery molecule phosphine, PH3, these clouds has reinvigorated research looking into possibility clouds. In review examine background studies on Venus, discuss conflicting and confirming observations analyses, look forward future space missions that will hopefully provide definitive answers origin phosphine question whether exist there.

Язык: Английский

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An Experimental Approach to Inform Venus Astrobiology Mission Design and Science Objectives

Aerospace, Год журнала: 2022, Номер 9(10), С. 597 - 597

Опубликована: Окт. 13, 2022

Exploring how life is distributed in the universe an extraordinary interdisciplinary challenge, but increasingly subject to testable hypotheses. Biology has emerged and flourished on at least one planet, that renders search for elsewhere a scientific question. We cannot hope travel exoplanets pursuit of other even if we identify convincing biosignatures, do have direct access planets moons our solar system. It therefore matter deep astrobiological interest study their histories environments, whether or not they harbor life, better understand constraints delimit emergence persistence biology any context. In this perspective, argue targeted chemistry- biology-inspired experiments are informative development instruments space missions, essential interpreting data generate. This approach especially useful studying Venus because it were exoplanet would categorize as Earth-like based its mass orbital distance, atmosphere surface decidedly Earth-like. Here, present general justification exploring system from destinations may life. introduce extreme environments Venus, rigorous observation-driven can guide instrument imminent missions Venusian clouds. highlight several specific examples, including organic chemistry under conditions, harnessing fluorescent properties molecules make variety otherwise challenging measurements.

Язык: Английский

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A Novel Abiotic Pathway for Phosphine Synthesis over Acidic Dust in Venus' Atmosphere

Astrobiology, Год журнала: 2024, Номер 24(4), С. 407 - 422

Опубликована: Апрель 1, 2024

Recent ground-based observations of Venus have detected a single spectral feature consistent with phosphine (PH3) in the middle atmosphere, gas which has been suggested as biosignature on rocky planets. The presence PH3 oxidized atmosphere not yet explained by any abiotic process. However, state-of-the-art experimental and theoretical research published previous works demonstrated photochemical origin another potential biosignature—the hydride methane—from carbon dioxide over acidic mineral surfaces Mars. production methane includes formation HC · O radical. Our density functional theory (DFT) calculations predict an energetically plausible reaction network leading to PH3, involving either or H· radicals. We suggest that, similarly minerals already discussed for Mars, Venus' could be radical chemistry starting ·PO HC·O, latter being produced reduction CO2 dust upper atmospheric layers ultraviolet radiation. HPO, H2P·O, H3P·OH identified key intermediate species our model pathway synthesis.

Язык: Английский

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Venus

Elsevier eBooks, Год журнала: 2024, Номер unknown, С. 289 - 323

Опубликована: Авг. 29, 2024

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The Habitability of Venus and a Comparison to Early Earth

Опубликована: Ноя. 7, 2022

Venus today is inhospitable at the surface, its average temperature of 750 K being incompatible to existence life as we know it. However, potential for past surface habitability and upper atmosphere (cloud) present day hotly debated, ongoing discussion regarding a possible phosphine signature coming from clouds shows. We review current understanding about evolution with special attention scenarios where planet may have been capable hosting microbial life. compare possibility on case Earth by reviewing various hypotheses put forth concerning origin habitable conditions emergence plate tectonics both planets. Life emerged during Hadean when was dominated higher mantle temperatures (by 200$^\circ$C), an uncertain tectonic regime that likely included squishy lid/plume-lid tectonics, proto continents. Despite lack well-preserved crust dating Hadean-Paleoarchean eons, attempt resume environmental this critical period based zircon crystals geochemical signatures period, well studies younger, relatively rocks Paleoarchean. For these early, primitive forms, not but it became important means nutrient recycling, consequences global environment long-term, essential continuation early Venus, question stable water closely related tectonics. discuss transitions between stagnant lid (episodic) crustal volatile cycling Venus’ interior atmosphere. In particular, insights into climate examine questions rotation speed, reflective clouds, silicate weathering, summarize implications long-term habitability. Finally, state knowledge venusian proposed detection covered.

Язык: Английский

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