2008/08/13 by Linda T. Elkins‐Tanton, L. Elkins-Tanton, Sara Seager +1 · 1 citation
Physics and Astronomy · #Accretion (finance) #Astronomy and Astrophysical Research #Exoplanet #Metal #Planet #Planetary mass #RADIUS #Scientific Research and Discoveries #Silicate #Stellar, planetary, and galactic studies #Terrestrial planet #astro-ph
paper · pdf · doi:10.1086/592316
ApJ, in press. 22 pages, 5 figures
arxiv created 2008/08/13 · openalex publication_date 2008/11/07 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Differentiation in terrestrial planets is expected to include the formation of a metallic iron core. We predict the existence of terrestrial planets that have differentiated but have no metallic core, planets that are effectively a giant silicate mantle. We discuss two paths to forming a coreless terrestrial planet, whereby the oxidation state during planetary accretion and solidification will determine the size or existence of any metallic core. Under this hypothesis, any metallic iron in the bulk accreting material is oxidized by water, binding the iron in the form of iron oxide into the silicate minerals of the planetary mantle. The existence of such silicate planets has consequences for interpreting the compositions and interior density structures of exoplanets based on their mass and radius measurements.