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

Daniele Antonangeli^a,¹,Guillaume Morard^a,Nicholas C. Schmerr^b,Tetsuya Komabayashi^c,Michael Krisch^d,Guillaume Fiquet^a, and Yingwei Fei^e., “Toward a mineral physics reference model for the Moon’s core”, Proc. Nat. Ac. Sc., 112(13), 3916–3919.

Author Affiliations

^aInstitut de Minéralogie, de Physique des Matériaux, et de Cosmochimie, UMR CNRS 7590, Sorbonne Universités – UPMC, Muséum National d’Histoire Naturelle, IRD Unité 206, 75252 Paris, France;

^bDepartment of Geology, University of Maryland, College Park, MD 20742;

^cDepartment of Earth and Planetary Sciences, Tokyo Institute of Technology, Tokyo 152-8551, Japan;

^dEuropean Synchrotron Radiation Facility, 38043 Grenoble Cedex, France; and

^eGeophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015

Edited by Ho-kwang Mao, Carnegie Institution of Washington, Washington, DC, and approved February 20, 2015 (received for review September 10, 2014)

 Abstract

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.

http://www.pnas.org/content/112/13/3916.abstract