Toward a mineral physics reference model for the Moon’s core

Daniele Antonangeli (1) , Guillaume Morard (1) , Nicholas C. Schmerr (2) , Tetsuya Komabayashi (3) , Michael Krisch (4) , Guillaume Fiquet (1) , Yingwei Fei (5)

1 IMPMC - Institut de minéralogie, de physique des matériaux et de cosmochimie
2 Department of Geology [College Park]
3 Department of Earth and Planetary Science [Tokyo]
4 ESRF - European Synchrotron Radiation Facility
5 Geophysical Laboratory [Carnegie Institution]

Iron is the main constituent of terrestrial planetary cores, taking on a hexagonal closed packed structure under the conditions of Earth’s inner core, and a face-centered cubic (fcc) structure at the more moderate pressures of smaller bodies, such as the Moon, Mercury, or Mars. Here we present sound velocity and density measurements of fcc iron at pressures and temperatures characteristic of small planetary interiors. The results indicate that the seismic velocities currently proposed for the Moon’s inner core are well below those of fcc iron or plausible iron alloys. Our dataset provides strong constraints to seismic models of the lunar core and cores of small telluric planets, and allows us to build a direct compositional and velocity model of the Moon’s core.

Domaines: Planète et Univers [physics]

Daniele Antonangeli, Guillaume Morard, Nicholas C. Schmerr, Tetsuya Komabayashi, Michael Krisch, et al.. Toward a mineral physics reference model for the Moon’s core. Proceedings of the National Academy of Sciences of the United States of America, 2015, sous presse. ⟨10.1073/pnas.1417490112⟩. ⟨hal-01134271⟩