Venus

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

By Keith Cowing

Status Report

Astrobiology via PubMed

September 30, 2024

Filed under amino acids, atmosphere, biochemistry, biosignature, Clouds, habitability, organic chemistry, sulfuric acid, Venus

Stability of 20 Biogenic Amino Acids in Concentrated Sulfuric Acid: Implications for the Habitability of Venus’ Clouds — A synthesized false color image of Venus using 283-nm and 365-nm images taken by UVI. Images are colorized as follows: 283 nm → blue; 365 nm → red; mixture of both → green. In the 283 nm band observed by UVI, there is an absorption band of sulfur dioxide (SO2). Also, there is an absorption band of an unidentified chemical substance in the 365 nm band. For example, it can be said that the amount of SO2 is relatively low in the bluish areas in this image. © PLANET-C Project Team — JAXA Larger image

Scientists have long speculated about the potential habitability of Venus, not at the 700K surface, but in the cloud layers located at 48–60 km altitudes, where temperatures match those found on Earth’s surface.

However, the prevailing belief has been that Venus’ clouds cannot support life due to the cloud chemical composition of concentrated sulfuric acid—a highly aggressive solvent. In this work, we study 20 biogenic amino acids at the range of Venus’ cloud sulfuric acid concentrations (81% and 98% w/w, the rest water) and temperatures.

We find 19 of the biogenic amino acids we tested are either unreactive (13 in 98% w/w and 12 in 81% w/w) or chemically modified in the side chain only, after 4 weeks.

Our major finding, therefore, is that the amino acid backbone remains intact in concentrated sulfuric acid. These findings significantly broaden the range of biologically relevant molecules that could be components of a biochemistry based on a concentrated sulfuric acid solvent.

Stability of 20 Biogenic Amino Acids in Concentrated Sulfuric Acid: Implications for the Habitability of Venus’ Clouds, Astrobiology. April 2024; 24(4): 386–396. Published online 2024 Apr 10. doi: 10.1089/ast.2023.0082 PMCID: PMC11035925PMID: 38498680(open access) via PubMed

Astrobiology

Keith Cowing

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻

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