Invited Talk at EU COST Action PLANETS Seminar

Abstract

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 Heavy Bombardment. 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.

Klaus Paschek

Postdoc - Astrophysics

My research interests include prebiotic synthesis, planetary science, and the origins of life.