Department of Complexity Science and Engineering, Graduate School of Frontier Science, University of Tokyo
Department of Complexity Science and Engineering, Graduate School of Frontier Science, University of Tokyo
Department of Complexity Science and Engineering, Graduate School of Frontier Science, University of Tokyo
Institute for Research on Earth Evolution, Japan agency for Marine-Earth Science and Technology (JAMSTEC)(IFREE)
Department of Earth and Planetary Science, University of Tokyo
Institute of Laser Engineering, Osaka University
Institute for Study of the Earth's Interior, Okayama Univerisity
Department of Complexity Science and Engineering, Graduate School of Frontier Science, University of Tokyo
出版者
宇宙航空研究開発機構宇宙科学研究本部
出版者（英）
Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)
雑誌名
Proceedings of the ISAS lunar and planetary symposium
巻
41
ページ
163 - 167
発行年
2009
会議概要（会議名, 開催地, 会期, 主催者等）（英）
The 41st ISAS Lunar and Planetary Symposium (August 6-8, 2008. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA))
抄録（英）
Cyanide compounds are considered as one of the most important molecules in the chemical evolution phase of the origin of life. However, the production process of cyanides in the surface environment of early Earth is still highly uncertain. Recent experimental studies on hypervelocity impacts suggested that carbon-containing projectile efficiently interact with an ambient atmosphere during intense aerodynamic ablation in oblique impacts, leading to the production of CN radicals from carbon contained in the impactors and nitrogen in the ambient atmosphere. Nevertheless, the fate of CN radicals after the production is poorly understood. In this study, we conducted laser ablation experiments within gas mixtures of N2, CO2, and Ar to simulate the formation of the CN radicals by the hypervelocity oblique impacts and subsequent chemical reactions with the gas species in early Earth's atmosphere. We investigated the chemical composition and structure of the products condensed from laser－induced ablation vapors with graphite and cast iron targets using elemental analysis and infrared absorption spectroscopy. Our experimental results show that the amount of total nitrogen in the condensed material strongly depends on the composition of ambient gas mixtures, and reaches ca. 10 wt% in the products using nitrogen gas only. The depths of absorption bands of CN bonds increase with the partial pressure of N2 in ambient gas mixtures increases. These results indicate that laser-induced CN radicals are fixed into condensed products by generating CN bonds in its structure. Our results using cast iron targets also indicate that iron in the laser-induced ablation vapor helps the incorporation of CN radicals into the condensed materials. These experimental results suggest that the interaction between the carbon-containing impactors and the N2 atmosphere may supply complex cyanide compounds as condensed products to the primitive oceans and/or lakes of early Earth, which may played an important role in the origin of life.
内容記述（英）
Physical characteristics: Original contains color illustrations
Cyanide production by chemical reactions between impactor material and an ambient atmosphere after oblique impacts
