Title: Extraterrestrial Contributions to the Prebiotic Inventory of the Early Earth from Meteorites
Monday, November 13, 2017
Abstract: Meteorites, in particular the 4% of carbonaceous chondrites that fall to the Earth, represent some of the most primitive and unaltered bodies in the solar system that we are able to study, and could have contributed an extraterrestrial source of organics to the prebiotic Earth. Of particular interest is the presence of amino acids and related compounds which could have yielded active length peptides within the primordial environment either directly or by production within the heated environment. The amino acids and associated species are found to be in high abundance within certain types of carbonaceous chondrites (specifically CM2 and CR2 groups), presenting an opportunity to try to answer some key questions, such as: i) Are amino acids incorporated into meteorites or formed within them? ii) To what extent are these species present as free acids vs. polymeric forms within the meteorite? iii) Are there spatial associations between acids or polymer abundances with the mineral/metal components found within meteorites? And iv) Does the temperature and history of the meteorite parent body play a role in their abundances and play a role in their production/destruction mechanism?
Here, we present some recent work investigating the process of the polymerization process on mineral surfaces as well as looking for evidences of these processes by looking at the Murchison (CM2), Allende (CV3), Jbilet Winselwan (CM2), and Tagish Lake (C2?) meteorites. A correlated approach is outlined whereby techniques including Raman and FTIR microscopy, TEM, ToF-SIMS, and some preliminary work using ESI-MS and nanoIR are helping to shed light on some of these questions.