CHEMICAL DIFFERENTIATION IN PLANETESIMALS IN THE EARLY SOLAR SYSTEM LEADS TO MELTING OF BOTH METALLIC AND SILICATE PHASES. THE SEGREGATION OF THESE MELTS WITH OPPOSITE BUOYANCY OCCURS EITHER IN A COMPACTING POROUS MEDIUM OR IN A MAGMA OCEAN. THE PROCESS OF CORE FORMATION IMPRINTS DISTINCT GEOCHEMICAL SIGNATURES ON THE DIFFERENTIATED BODY AND AFFECTS THE THERMAL HISTORY OF THE PLANETESIMAL AND THEREFORE THE COOLING HISTORY OF THE CORE. HYPOTHESES ABOUT THE LATTER WILL BECOME TESTABLE FOR THE FIRST TIME WITH THE UPCOMING NASA MISSION TO METAL ASTEROID 16 PSYCHE. TO DETERMINE THE TIMING OF CORE FORMATION IN PLANETESIMALS WE PROPOSE TO IMPROVE THE DESCRIPTION OF SIMULTANEOUS METAL AND SILICATE MELT PERCOLATION IN A COMPACTING POROUS MEDIUM. THE DYNAMICS OF THIS PROCESS INVOLVE A COMPLEX COUPLING ACROSS THE SCALES. THE LARGE-SCALE REDISTRIBUTION OF ENERGY AND MASS DEPENDS ON PORE-SCALE INTERACTIONS BETWEEN THE TWO MELTS. THEREFORE WE PROPOSE THE DEVELOPMENT OF NOVEL A MULTISCALE MODEL WHERE THE CONSTITUTIVE LAWS FOR THE MACROSCOPIC EVOLUTION EQUATIONS ARE DETERMINED BY PORE-SCALE SIMULATIONS.

University Of Texas At Austin, Austin TX

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