The conditions for the potential abiotic formation of organic compounds from inorganic precursors have great implications for our understanding of the origin of life on Earth and for its possible detection in other environments of the Solar System. It is known that aerosol-interfaces are effective at enhancing prebiotic chemical reactions, but the roles of salinity and pH have been poorly investigated to date. Here, we experimentally demonstrate the uniqueness of alkaline aerosols as prebiotic reactors that produce an undifferentiated accumulation of a variety of multi-carbon biomolecules resulting from high-energy processes (in our case, electrical discharges). Using simulation experiments, we demonstrate that the detection of important biomolecules in tholins increases when plausible and particular local planetary environmental conditions are simulated. A greater diversity in amino acids, carboxylic acids, N-heterocycles, and ketoacids, such as glyoxylic and pyruvic acid, was identified in tholins synthetized from reduced and neutral atmospheres in the presence of alkaline aqueous aerosols than that from the same atmospheres but using neutral or acidic aqueous aerosols.
The authors used the research facilities of the Centro de Astrobiología (CAB) and were supported by the Instituto Nacional de Técnica Aeroespacial “Esteban Terradas” (INTA) and by the Spanish MINECO project ESP2014-55811-C2-2-P. M.R.M.-Y. was supported by a research training grant from INTA. C.M. and P.E. were fellows of “Plan de Formación” from INTA. M.-P.Z. and E.G.-T. acknowledge the Spanish MINECO projects CGL2014-55230-R and CGL2015-69758-P. Additionally, we are grateful to M.T. Fernández for the recording of the FT-IR spectra.
- Chemical origin of life