By looking at the range of isotopic variations in terrestrial and meteoritic samples, a Lawrence Livermore National Laboratory (LLNL) scientist and collaborators have figured out that Earth and
Determining which of the two processes governed the formation of the terrestrial planets of our solar system is crucial for understanding the solar system’s architecture and dynamical evolution, and for placing planet formation in the solar system into the context of general planet formation processes, such as those observed in exoplanetary systems.
The amount of outer solar system material accreted by the terrestrial planets may be determined using nucleosynthetic isotope anomalies. These arise from the heterogeneous distribution of presolar matter within the solar protoplanetary disk and provide a record of the heritage of a planet’s building material. These isotope anomalies permit distinguishing between non-carbonaceous (NC) and carbonaceous (CC) meteorites, which are commonly assumed to represent planetary bodies that accreted in the inner and outer solar system, respectively.
The team used the recent observation of correlated isotope variations among NC meteorites to show that both Earth and Mars incorporated material unsampled among meteorites, determined the provenance and isotopic composition of this lost planetary building material and used this information to assess the amount of CC material accreted by Earth and Mars.
For more on this research, see Earth and Mars Were Formed From Collisions of Large Bodies Made of Inner Solar System Material.
Reference: “Terrestrial planet formation from lost inner solar system material” by Christoph Burkhardt, Fridolin Spitzer, Alessandro Morbidelli, Gerrit Budde, Jan H. Render, Thomas S. Kruijer and Thorsten Kleine, 22 December 2021, Science Advances.
Other contributors include researchers from the University of Münster, the Université de Nice Sophia-Antipolis, the California Institute of Technology and the Museum für Naturkunde and the Freie Universitat in Berlin. The work is funded by the German Research Foundation.