Meteorites and the RNA World: Synthesis of Nucleobases in Carbonaceous Planetesimals and the Role of Initial Volatile Content

Prebiotic molecules, fundamental building blocks for the origin of life, have been found in carbonaceous chondrites. The exogenous delivery these organic molecules onto Hadean Earth could sparked polymerization first RNA Darwinian ponds during wet-dry cycles. Here, we investigate formation and DNA nucleobases adenine, uracil, cytosine, guanine, thymine inside parent body planetesimals An up-to-date thermochemical equilibrium model coupled with a 1D thermodynamic planetesimal is used to calculate nucleobase concentrations. Different from previous study (Pearce & Pudritz 2016), assume initial volatile concentrations more appropriate zone chondrite bodies. This represents accurately cosmochemical findings that bodies formed inner, $\sim 2\mathrm{-}5\,\mathrm{au}$, warm region solar system. Due improvements, our adenine guanine measured Our did not reproduce per se measurements meteorites. can be explained by transformation reactions between potential decomposition thymine. synthesis prebiotic matter asteroids well combination i) radiogenic heating, ii) aqueous chemistry involving few key processes at specific range radii where water exist liquid phase, iii) reduced content (H$_2$, CO, HCN, CH$_2$O) protoplanetary disk material compared outer comets.