Note: Organic matter does not mean life. It is a precursor to life. It does make the possibility of life on ancient Mars more likely.

  • TauZero
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    1 year ago

    Chemists: If it contains carbon it's organic

    Anyway, here’s the Nature paper:
    https://doi.org/10.1038/s41586-023-06143-z

    And here’s the table listing the actual organic molecules detected:
    https://www.nature.com/articles/s41586-023-06143-z/tables/3
    Including benzene and naphthalene, and amine acids lysine, tyrosine, phenylalanine, histidine, etc.

    Curiously, only L-amino acids were detected. Did they test for D-aa and didn’t see any, or did they test for L-aa only? The paper doesn’t say. If the former, that’s a pretty big deal. As far as I know there is no inorganic process that can produce non-racemic chiral molecules.

    • TauZero
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      1 year ago

      Ah! This reference paper goes into more detail about how the reference spectra for the Raman fluorescence were acquired: https://doi.org/10.1089/ast.2022.0023 They built a fluorescence spectrometer identical to the SHERLOC tool onboard the Perseverance rover on Mars and tested it against a library of molecules of interest, including all L-amino acids and a few of the D-amino acids. Turns out the spectrometer cannot differentiate between the two:

      The fluorescence spectra of d-phenylalanine and l-phenylalanine were almost identical, showing no obvious dependence on the chirality of the α-carbon.

      Raman fluorescence spectra of 20 amino acids