Contributed talk at BEACON 2025

Abstract

The emergence of life on Earth required reducing conditions, yet geological record suggests an early oxidizing atmosphere. How, then, was the primordial soup prepared? We address this question by extending a photochemical model of the Hadean atmosphere to evaluate different sources of reducing gases, such as serpentinization and the bombardment of enstatite and carbonaceous meteorites. Coupling this with a wet-dry cycling model, we estimate the concentrations of key prebiotic molecules in warm little ponds (WLPs). Our results show that an H2-rich atmosphere, dominated by carbonaceous impacts, could yield millimolar nucleobase concentrations, while a CO2-dominated atmosphere reduced by serpentinization yields concentrations an order of magnitude lower. In both cases, these levels are sufficient for nucleotide synthesis, suggesting that RNA could have emerged soon after Earth became habitable 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.