Formation of a terrestrial planet from lost material from the inner solar system
Two fundamentally different processes for the formation of rocky planets exist, but it is unclear which built the terrestrial planets of the solar system.
Either they were formed by collisions between planetary embryos of the inner solar system, or by accreting millimeter “pebbles” drifting towards the sun of the outer solar system. We show that the isotopic compositions of Earth and Mars are governed by two-component mixing among inner Solar System materials, including materials from the innermost disk not sampled by meteorites, whereas the contribution of materials from the outer solar system is limited to a few percent by mass.
This disproves a pebble accretion origin from the telluric planets, but is consistent with the collisional growth of inner solar system embryos. The low fraction of outer solar system material on Earth and Mars indicates the presence of a persistent barrier of dust and drift in the disc, highlighting the specific pathway of formation of rocky planets in the solar system.
Christoph Burkhardt, Fridolin Spitzer, Alessandro Morbidelli, Gerrit Budde, Jan H. Render, Thomas S. Kruijer, Thorsten Kleine
Comments: combined main test + published article supplement
Subjects: Terrestrial and planetary astrophysics (astro-ph.EP)
Journal reference: Science Advances 7, 52, abj7601 (2021)
Cite as: arXiv:2201.08092 [astro-ph.EP] (or arXiv:2201.08092v1 [astro-ph.EP] for this release)
By: Christoph Burkhardt
[v1] Thu Jan 20 2022 09:44:53 UTC (1,415 KB)