Simulating Amino Acid Formation in Small Bodies:Formaldehyde-Ammonia vs. Hexamethylenetetramine Pathways

Abstract

In this study, we conducted heating experiments simulating small bodies to evaluate how the type of starting material and heating duration affect the yield of amino acids. As starting materials, we used formaldehyde and ammonia, which are abundant in comets and are therefore expected to have been present in unaltered parent bodies, as well as hexamethylenetetramine (HMT), which has been identified as a product in experiments simulating interstellar ices. The results of this study showed that longer heating durations led to the formation of a greater variety of amino acids, with a trend toward increased carbon numbers. Using HMT as the starting material yielded a comparable amount of amino acids to the formaldehyde-ammonia system. Given its lower volatility compared to ammonia, HMT could have served as a nitrogen source for organic synthesis inside the ammonia snow line. We also plan to evaluate the relationship between the remaining amount of formaldehyde and the yield of amino acids.