Impact-generated Atmospheres on the Early Earth

Little is known about the evolution of the Early Earth atmosphere at the end of the Hadean, after the solidification of the magma ocean and before the emergence of life. As shown by the Miller-Urey experiments, the building blocks of life can form easily in a reduced atmosphere, however, based on the study of volcanic gasses, it is thought that the Early Earth atmosphere was likely oxidized. We are looking at the possibility that impacts could generate transient reduced atmospheres on the Early Earth. We present the first results related to the chemistry generated by different impactor types, and model the structure and composition of the Earth's atmosphere following such events. Finally, we calculate the cooling timescales and estimate the atmospheric evolution in these scenarios.