[B-CG09] Decoding the history of Earth: From Hadean to the present

[BCG09-02] The roles of hypervelocity impacts on the surface evolution of the Hadean Earth

★Invited Papers

*Kosuke Kurosawa¹, Takaya Okamoto¹, Hikaru Yabuta², Goro Komatsu³, Takafumi Matsui¹ (1.Planetary Exploration Research Center, Chiba Institute of Technology, 2.Dept. Earth and Planet. Sys. Science, Hiroshima University, 3.International Research School of Planetary Sciences, Università d'Annunzio)

Keywords:Hypervelocity imapcts, Post-impact chemistry, Two-stage hydrogen gas gun, In-situ gas phase analysis, Quadrupole mass spectrometer

Impact bombardments are the main driving forces of the surface evolution on the Hadean Earth. Typical impact velocity onto the Earth is estimated to become 20 km/s, resulting in an extremely-high energy density to be about 200 MJ/kg. The energy density corresponds to a temperature and pressure of 200000 K and 600 GPa, respectively. Thus, hypervelocity impacts would cause physical/chemical processes, which is never driven under the mean field on the Hadean Earth, resulting in an intense and impulsive catastrophic perturbation. Chemical products produced by such high-energy collisions might be fixed into ancient stratifications as unique chemical features. We are constructing a new experimental system at Planetary Exploration Research Center of Chiba Institute of Technology to understand the roles of impact-driven chemical processes on the surface environment on the Hadean Earth. In the presentation, we will present a brief review about the thermodynamics behind the impact-driven processes and will discuss a future plan induced by the new experimental system.