講演情報
[PPS04-P24]Deposition of the Ancient Earth’s Atmosphere in the Lunar Regolith
*Jared Brack Landry1、Tatsuya Yoshida1、Hidenori Genda1、Hiroyuki Kurokawa2,3 (1.Earth-Life Science Institute、2.Department of General Systems Studies, The University of Tokyo、3.Department of Earth and Planetary Sciences, The University of Tokyo)
キーワード：
Atmospheric Evolution、Ionization、Lunar Regolith、Atmospheric Escape
The evolution of the Earth’s atmosphere, particularly the early atmosphere, is still poorly understood. By comprehensively investigating it, we can begin to constrain what the ancient environment might have looked like where life emerged and evolved. Previous literature has theorized that ions from the Earth’s atmosphere have been deposited on the lunar surface (Ozima et al., 2005; Terada et al., 2017). Therefore, the evolution of the Earth’s atmosphere should be recorded in the uppermost layers of the lunar surface. To properly deconstruct data collected from the Apollo missions and lunar meteorites, we also take into account deposition of material from the Solar wind, lunar interior, and interstellar medium. Then, using Bayesian analysis, we determine the necessary contribution of the terrestrial component of H, C, N, O, and Ar ions to the lunar regolith. These fluxes are then used alongside a one-dimensional ionization model that determines the best fit atmospheric composition capable of reproducing the fluxes determined in the previous step. The results will elucidate the history and evolution of the Earth-Moon system, giving insight into the environment where life may have formed and evolved, and answering many questions about the Earth’s ancient atmosphere.