[M-IS20] 水惑星学

[MIS20-06] Role of mineral catalysis on the molecular evolution of Solar System bodies

*LI Yamei¹、Hiroyuki Kurokawa¹、Yasuhito Sekine^1,2、Yoko Kebukawa³、Yuko Nakano¹、Norio Kitadai⁴、Naizhong Zhang⁵、Xiaofeng Zang⁵、Yuichiro Ueno^1,5、Ryuhei Nakamura¹、Kosuke Fujishima¹、Junko Isa⁶ (1.Earth-Life science Institute, Tokyo Institute of Technology、2.Institute of Nature and Environmental Technology, Kanazawa University、3.Yokohama National University、4.Japan Agency for Marine-Earth Science and Technology、5.Department of Earth and Planetary Sciences, Tokyo Institute of Technology、6.Planetary Exploration Research Center, Chiba Institute of Technology)

キーワード：Origins of life, Amino acids, Carbonaceous chondrite, Asteroid Ryugu, Mineral catalysis, Electrochemistry

The origins of life on early Earth and other habitable environments remain to be solved. The exploration of this question provides a critical guide for deep-Earth and extraterrestrial life exploration and evaluating the habitability of extraterrestrial bodies. One of the central questions is the origin, evolution, and distribution of life’s building block molecules in the context of Solar System evolution. Water/rock interaction systems distribute widely on Earth, early Mars, and icy satellites (e.g., Enceladus). Such systems are closely related to these bodies’ habitability because they can possibly provide water, energy as well as organics in one place that is considered to be required for life emergence. Besides these inner system bodies, at the early stage of Solar System evolution, the icy planetesimals formed beyond the water snow line also featured water/rock interactions. These water/rock interactions could have created and/or decomposed organic compounds. Based on the observations on carbonaceous chondrites and recent return samples from C-type asteroid Ryugu, life’s critical building block, namely amino acids, could have been widely distributed in our Solar System and thus contributed to the life emergence on the Early Earth and possibly elsewhere. The amino acid abundance records suggest the important role of parent body water/rock interactions in shaping their distributions.
Here in my talk, I will introduce how water/rock interactions create an environment with thermodynamic disequilibria. Minerals can mediate the electron transfer to facilitate the energy conversion in the mode of geo-electrochemistry for either creating or decomposing life’s building block molecules.