Venus is often described as a hellscape. The surface temperature breaches the melting point of lead, and though its atmosphere is dominated by carbon dioxide, it contains enough sulfuric acid to satisfy the comparison with Hades. <\/p>\n
But conditions throughout Venus\u2019 ample atmosphere aren\u2019t uniform. There are locations where some of life\u2019s building blocks could resist the planet\u2019s inhospitable nature.<\/p>\n
<\/p>\n Among the rocky planets, Venus has by far the largest atmosphere by volume. So, while its surface is inhospitable, its atmosphere has regions that are the most Earth-like of anywhere else in the Solar System. Scientists have wondered if life could survive in parts of the planet\u2019s upper atmosphere, and the discovery of the potential biomarker phosphine (though it was later disproved) generated more interest. <\/p>\n One reason Venus keeps coming up in discussions around habitability is that it\u2019s accessible, whereas exoplanets aren\u2019t. Venus is easily reached, and we currently have one orbiter in place, the Japanese Akatsuki spacecraft. Three other missions to Venus are planned for the mid-2030s: NASA\u2019s Veritas and DAVINCI and the ESA\u2019s EnVision. <\/p>\n Nobody is convinced we\u2019ll find life on Venus. But the planet can teach us a lot about chemistry and biology and their limits. <\/p>\n In new research, a team of scientists tested different building blocks under Venus-like conditions to see if they can withstand the planet\u2019s perilous nature. The research is \u201cSimple lipids form stable higher-order structures in concentrated sulfuric acid.\u201d The lead author is Daniel Duzdevich from the Department of Chemistry at the University of Chicago. The paper is in pre-print now and has been submitted to the journal Astrobiology. <\/p>\n Venus\u2019 surface isn\u2019t a candidate for habitability. But regions in its atmosphere may be. The issue is that much of Venus\u2019 sulfuric acid is concentrated in discrete clouds rather than diffused throughout its atmosphere. <\/p>\n \u201cThe Venusian surface is sterilizing, but the cloud deck includes regions with temperatures and pressures conventionally considered compatible with life. However, the Venusian clouds are thought to consist of concentrated sulfuric acid,\u201d the authors explain. <\/p>\n They wanted to test if any of life\u2019s \u201cfundamental features\u201d could withstand Venus\u2019 challenging environment. Can any of life\u2019s chemistry resist sulfuric acid? <\/p>\n \u201cOrganic chemistry in concentrated sulfuric acid is rarely studied yet surprisingly rich, with recent work supporting the notion that complex organic molecules, including amino acids and nucleobases can be stable in this unusual solvent,\u201d the authors write. <\/p>\n If simple organic molecules can remain stable in sulfuric acid, it\u2019s an interesting observation in favour of life. But it takes more complexity than that, and that\u2019s what this research focuses on. <\/p>\n \u201cOne fundamental feature of life is cellularity: the differentiation of \u201cinside\u201d (the contents of a cell, including information, molecules, and all their interactions) and \u201coutside\u201d (the environment), in addition to a mechanism for communication and exchange between the two,\u201d Duzdevich and his co-researchers write. <\/p>\n The researchers focused on lipids, the membranes that define cells. Lipids are the foundation of cellular structure, not only as membranes between cells but also as membranes that create distinct parts of the interior of cells. \u201cThe cell membrane is especially important in extreme environments because it must help maintain the homeostasis of the intracellular environment against otherwise harsh external conditions,\u201d the authors write. <\/p>\n The researchers performed lab experiments to determine whether lipids can withstand Venus\u2019 harsh environment. They asked two questions: Can simple lipids resist decomposition by sulfuric acid, and can the lipids form stable higher-order structures like they do in cells?<\/p>\n The researchers placed masses of lipids in vials and exposed them to different concentrations of sulfuric acid and measured each vial at specific intervals. Their results show that some lipids can survive exposure to the acid and even form structures.<\/p>\n Interested readers can explore the detailed chemistry for themselves. <\/p>\n In summary, the results suggest that stable membranes can form and persist in the presence of sulfuric acid. Life uses water as a solvent because it\u2019s a polar molecule, can form networks of hydrogen bonds, has a high heat capacity, and, of course, is abundant on Earth. But it\u2019s not abundant everywhere. <\/p>\n Critically, this study shows that some aspects of the chemistry of life don\u2019t require water as a solvent. Instead, they can tolerate and use sulfuric acid as a solvent. \u201cHere, we show the unexpected stability of complex membranous structures in another polar solvent: concentrated sulfuric acid,\u201d the authors write. <\/p>\n What does this mean for exoplanet habitability and astrobiology?<\/p>\n \u201cConcentrated sulfuric acid as a planetary solvent could be widespread on exoplanets, either on exo-Venuses or on other rocky planets that are desiccated as a result of the stellar activity of their host star,\u201d the researchers explain. <\/p>\n And, of course, sulfuric acid is present in large amounts at Venus. <\/p>\n \u201cConcentrated sulfuric acid is also present in our immediate planetary vicinity as a dominant liquid in the clouds of Venus, further emphasizing its importance for planetary science, planetary habitability, and astrobiology,\u201d the authors write. <\/p>\n The question of whether life could somehow survive in Venus\u2019 clouds is one that won\u2019t go away. We\u2019re new at the astrobiology game, and we\u2019re simply not in a position to rule things out. It might seem far-fetched, but science is an evidence game, and evidence can be surprising.<\/p>\n This study doesn\u2019t present evidence that can answer the question\u2014big questions like this are answered incrementally\u2014but it does present an intriguing result. <\/p>\n \u201cBy demonstrating the stability of lipid membranes in this aggressive solvent, we have taken a significant step forward in exploring the potential habitability of the concentrated sulfuric acid cloud environment on Venus,\u201d the authors conclude. <\/p>\n![\"Cloud](\"https:\/\/www.universetoday.com\/wp-content\/uploads\/2021\/10\/Venus_-_December_23_2016.jpg\")
![\"This](\"https:\/\/www.universetoday.com\/wp-content\/uploads\/2024\/09\/lipid-structures.jpg\")
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