Report

Seismic Detection of the Lunar Core

Science  06 Jan 2011:

DOI: 10.1126/science.1199375

Abstract

Despite recent insight regarding the history and current state of the Moon from satellite sensing and analyses of limited Apollo-era seismic data, deficiencies remain in our understanding of the deep lunar interior. We reanalyzed Apollo lunar seismograms using array processing methods to search for the presence of reflected and converted seismic energy from the core. Our results suggest the presence of a solid inner and fluid outer core, overlain by a partially molten boundary layer. The relative sizes of the inner and outer core suggest that the core is ~60% liquid by volume. Based on phase diagrams of iron alloys and the presence of partial melt, the core likely contains less than 6 weight % of lighter alloying components, which is consistent with a volatile-depleted interior.