Reply to “Comment on ‘Prebiotic Chemistry Within a Simple Impacting Icy Mixture’”
In a recent article in this journal, we use quantum simulations to describe the possible formation of prebiotic material from impacting astrophysical icy mixtures on early Earth. Our model system included only simple starting materials found in cometary material, namely a mixture of 2 H 2 O:1 CO:1 CO 2 :1 CH 3 OH:1 NH 3 . Here, we have cycled this mixture sequentially through all of the thermodynamic states of an impact event: shock compression due to impact (high temperature, high pressure end states), expansion to ambient pressures (high temperature, low pressure end states), and cooling to ambient temperatures (low temperature, low pressure end states). Our results predicted that a number of prebiotic materials could be synthesized ultimately upon relaxing to a low temperature, low pressure state, including protein-forming amino acids. Amino acids and peptides are known to be metastable compounds with high activation energies for decomposition. Here, our predictions have since been confirmed by recent gas gun experiments on an icy mixture of similar composition and at similar thermodynamic conditions to our studies, where the protein forming amino acids glycine and alanine were detected as end products.