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> to detect organic molecules in the atmosphere You don't really need to detect organic molecules. If anyone detected 21% oxygen (O2, inorganic) in Earth's atm
by sampo 3y ago
> to detect organic molecules in the atmosphere
You don't really need to detect organic molecules. If anyone detected 21% oxygen (O2, inorganic) in Earth's atmosphere, they sure knew something was going on. Lifeless planets like Venus, Mars, have atmospheres that are close to chemical equilibrium. And Earth's atmosphere is far from equilibrium, free oxygen it much too reactive and wouldn't exist without photosynthesis continuously producing it.
- gizmo686 3y agoAccording to NASA, abiotic production of O2 at Earth like levels is plausible. https://exoplanets.nasa.gov/news/215/oxygen-on-exoplanets-isnt-proof-of-life/ https://exoplanets.nasa.gov/news/215/oxygen-on-exoplanets-is... Our understanding of astrochemestry is still limited enough, that we cannot say with confidence that a given signature requires a biotic process to produce.
- sampo 3y agoLink to full text: https://www.nature.com/articles/srep13977 https://www.nature.com/articles/srep13977
- Shekelphile 3y ago> Our understanding of astrochemestry is still limited enough, that we cannot say with confidence that a given signature requires a biotic process to produce. It will always be possible to find a new extreme edge case to deny far easier and more common processes that leave around biosignatures, it's the exact same rhetoric used to handwave away the methane in the martian atmosphere.