[P-PS01] Outer Solar System Exploration Today, and Tomorrow

[PPS01-P03] Evolution of Icy Moon's Interior Uncovered by Laboratory Experiment: Modeling of Space Weather by Ion Irradiation

*木村 智樹¹、仲内 悠祐²、木村 淳³、鈴木 耕拓⁴、中田 吉則⁴、玉川 徹⁵、早藤 麻美⁵、中野 俊男⁵、村上 豪⁶、吉岡 和夫⁷ (1.東北大学学際科学フロンティア研究所、2.会津大学宇宙情報科学クラスター、3.大阪大学理学研究科、4.若狭湾エネルギー研究センター、5.理化学研究所仁科加速器研究センター、6.JAXA宇宙科学研究所、7.東京大学大学院新領域創成科学研究科)

キーワード：氷天体、地下海、プラズマ

In our solar system, several icy bodies have possibility for a liquid water ocean underneath a solid ice shell, while only Earth has ocean on the surface. The subsurface ocean could be potentially universal habitable environment. Duration of the subsurface ocean is an unsolved big problem for evolution of the icy body's interior and also for the possible life that has likely been evolving there. We uncover the evolutions of subsurface ocean based on the space weathering on solid surface that is driven by irradiation of energetic plasma around planets. Long-term space weathering at Ganymede that reaches Giga years is modeled by plasma irradiation to surface materials with laboratory beam experiment. Chronology for Ganymede's magnetic field excited by molten metallic core can be suggested based on a dependence of the space weathering on the Ganymede's magnetic field strength. We are going to pin down the subsurface ocean evolution from the magnetic field chronology. In this presentation, we report current status of our laboratory experiment made with an ion injector at Wakasa-wan Energy Research Center.