Sprecher
Beschreibung
Deep Mantle–Atmosphere Coupling and Carbonaceous Bombardment: Options for Biomolecule Formation on an Oxidized Early Earth
Klaus Paschek
The emergence of life on Earth required reducing conditions; however, the geological record suggests an early oxidizing atmosphere. How, then, was the primordial soup prepared? How can the Miller-Urey experiment be saved? We address these questions by extending a photochemical model of the Hadean atmosphere to evaluate the impact of different sources of reducing gases. These sources include volcanic serpentinization and the bombardment of enstatite and carbonaceous meteorites during the Late Veneer. By coupling this model with a wet-dry cycling model, we can estimate the concentrations of key prebiotic molecules in Darwinian ponds on early Earth. Our results demonstrate that a CO₂-rich atmosphere can be reduced by global serpentinization alone. This yields key building blocks of life at millimolar concentrations in the modeled ponds. These concentration levels are sufficient for nucleotide synthesis, producing the monomers of RNA. These findings suggest that RNA could have emerged soon after Earth became habitable and/or reappeared later during the Hadean-Archean transition.
Reference:
Paschek, K., Henning, T. K., Molaverdikhani, K., Miyazaki, Y., Pearce, B. K. D., Pudritz, R. E., Semenov, D. A. 2025, The Astrophysical Journal, 985, 50, doi: 10.3847/1538-4357/adc39b