Physical Properties and Composition of Cores of Terrestrial Planets

of Terrestrial Planets 寺崎 英紀 Hidenori TERASAKI To constrain the core compositions of terrestrial planets, sound velocity and density of liquid Fe  Ni  S and Fe  Ni  Si alloys were measured up to 14 GPa. Addition of S reduces the P-wave velocity and bulk modulus of liquid Fe  Ni while addition of Si rises the P-wave velocity and does not affect on the bulk modulus in the present pressure range. Based on the obtained elastic properties of liquid Fe  Ni  S and Fe  Ni  Si, the compositions of planetary cores are estimated by matching the planetary geodesy data to 3  7 wt  S or wt