Exoplanet Mineralogy

Abstract

Mineral properties hold dominion over planetary behavior as their physical and thermal properties control mantle circulation, plate tectonics, melting behavior, and crustal deformation, as well as global water and CO2 cycles. Estimating exoplanet mineralogy is thus of paramount importance for understanding planetary origins and evolution. Preliminary studies of exoplanets emphasize individual element abundances (e.g., Ca or K contents) or ratios (Mg/Si or Si/Fe), which are a valuable first step. But inter-planetary differences in, say, Si or Mg, are only relevant insofar they define a planet’s mineralogy.As will be shown, nothing definitive can yet be said about exoplanet mineralogy,...