Dix Planetary Science Seminar

Abstract: Science missions to comets and moons in our solar system have returned surprising results about the presence and abundance of small molecules, such as H2, O2, CH3OH, and even Glycine, whose origin remains a mystery especially under the extreme conditions of outer space. Understanding how such molecules form may impact manned missions to other planets by permitting in-situ resource utilization for propulsion and sustenance of life. This talk will explore new and unusual reaction dynamics of energetic H2O and CO2 molecules colliding with surfaces of astrophysical relevance, where reaction barriers are overcome by kinetic energy. Three such reactions will be discussed: (i) the splitting of water directly into molecular H2 and atomic oxygen in single collisions of water ions with generic surfaces, (ii) the abstraction of oxygen from oxidized surfaces by water ions, which leads to facile production of molecular O2 and (iii) the collisional dissociation of CO2 directly into O2 and atomic carbon. The former reaction provides abiotic explanations for the origin of the H2 discovered recently on Enceladus, while the latter two explain some of the O2 found in abundance on comet 67P. The collisional dissociation of CO2 using plasmas may offer a simpler way to generate oxygen on planets with CO2 atmospheres while providing new terrestrial negative emissions technologies.