[P-PS03] 太陽系小天体：太陽系進化における最新成果と今後の展望

[PPS03-15] In-Situ Mass Spectrometry for Interstellar Dust in Space Missions: A Novel Approach to Study the Physical and Chemical Properties of the Local Interstellar Cloud

*木村 宏¹、Frank Postberg²、Mario Trieloff³、Nicolas Altobelli⁴、Harald Krüger⁵、Seth Redfield⁶、小林 正規¹、荒井 朋子¹、平井 隆之¹、伊藤 元雄⁷、Peter Strub⁵ (1.千葉工業大学惑星探査研究センター、2.Freie Universität Berlin、3.University of Heidelberg、4.ESA-ESAC、5.Max Planck Institute for Solar System Research、6.Wesleyan University、7.JAMSTEC)

In-situ mass spectrometry for dust particles streaming into the inner Solar System from the Local Interstellar Cloud (LIC) is a promising technique to measure the abundances of the chemical elements in the solid phase of the LIC. In contrast, remote-sensing spectroscopic observations of gas-phase ab- sorption lines towards nearby stars provide us the opportunity of inferring the elemental abundances of dust in the LIC from the depletion of the elements in the LIC gas. Therefore, in-situ mass spectro- metric measurements of the elements in the solid phase and remote-sensing spectroscopic observations of the elements in the gas phase are complementary to each other with regard to the determination of elemental abundances. We show how the chemical composition of interstellar dust measured in situ acts as a powerful tool to constrain the gas-phase abundances and ionization states of the elements undetectable by spectroscopic observations. In-situ mass spectrometry for the LIC dust is also of great importance for placing a constraint on the age of the LIC dust in combination with laboratory anal- yses of radioactive isotopes originating from the LIC. We conclude that in-situ mass spectrometry for interstellar dust in space missions is a novel approach to study the physical and chemical properties of the LIC.