Coupled atmospHere Interior modeL Intercomparison (CHILI). I. Evolutionary Modelling -- Primordial Magma Oceans of Earth and Venus

arXiv (Cornell University)

Abstract

Earth and Venus represent two evolutionary outcomes arising from initially molten 'magma ocean' periods, followed by lifetimes of chemical and geophysical divergence. Their physics is common to all rocky planets and is accessible to simulations that adopt coupled interior-atmosphere modelling approaches. Our understanding of planet histories and interpretation of current states is dependent on this modelling, yet existing codes vary in their approximations. Here, we present the first results from the Coupled atmospHere Interior modeL Intercomparison (CHILI) project; benchmarking planetary evolution codes in the context of Earth and Venus to identify key model sensitivities. Our 'nominal' Earth models predict magma ocean solidification timescales within 4 Myr of thermal evolution, and are consistent with empirical constraints on Earth's early history. Venus scenarios exhibit more diverse behaviours where prolonged magma ocean stages can be conditionally sustained for 50 Myr. Cooling timescales correlate with initial hydrogen and carbon budgets, but model-specific treatments of volatile partitioning and vertical energy transport introduce substantial inter-model variance. Different parametrisations of mantle geodynamics, convection, melting curves, rheological properties, and radiative transfer give rise to divergent evolutionary behaviours. Discrepancies in atmospheres generated by magma ocean outgassing underscore these differences, although C-H-O compositions with surface pressures exceeding 100 bar are favoured. This intercomparison identifies critical sensitivities in volatile partitioning, escape processes, mantle viscosity, and melting. Validating these treatments is essential for enabling deep insight into the early histories of the Solar System's terrestrial planets, and for drawing meaningful interpretations from ongoing observational exoplanet campaigns.

Authors 25

1. Harrison Nicholls
2. Joshua Krissansen‐Totton
3. Lichtenberg Tim

   University of Groningen

   Affiliation as printed

   Kapteyn Astronomical Institute , University of Groningen , The Netherlands

4. Laura Schaefer

   Stanford University

   Affiliation as printed

   Stanford University , USA

5. Keiko Hamano

   National Astronomical Observatory of Japan

   Affiliation as printed

   National Astronomical Observatory of Japan , Japan

6. Maxime Maurice

   Laboratoire de Mathématiques Blaise Pascal

   Affiliation as printed

   Laboratoire de Mathématiques de Versailles , France

7. Henri Samuel

   Centre National de la Recherche Scientifique · Institut de physique du globe de Paris · Université Paris Cité

   Affiliation as printed

   Université Paris Cité , Institut de physique du globe de Paris , CNRS , Paris , France

8. Alexandra Papesh

   University of Washington

   Affiliation as printed

   University of Washington , USA

9. Carlos Ortiz-Quintana
10. Junellie Perez

    Johns Hopkins University

    Affiliation as printed

    Johns Hopkins University , USA

11. Yamila Miguel Aachen Leiden Observatory SRON Netherlands Research Organisation Netherlands

    Leiden University · Leiden Observatory · Space Research Organisation Netherlands

    Affiliation as printed

    Leiden Observatory , University of Leiden , Einsteinweg 55 , 2333CA Leiden , The Netherlands

    SRON Netherlands Research Organisation Netherlands , Niels Bohrweg 4 , 2333CA Leiden , The Netherlands

12. Denis E. Sergeev

    University of Bristol

    Affiliation as printed

    School of Physics , University of Bristol , UK

13. Philipp Baumeister
14. Spanan Dash
15. Leoni Janssen Aachen Leiden Observatory SRON Netherlands Research Organisation Netherlands

    Leiden University · Leiden Observatory · Space Research Organisation Netherlands

    Affiliation as printed

    Leiden Observatory , University of Leiden , Einsteinweg 55 , 2333CA Leiden , The Netherlands

    SRON Netherlands Research Organisation Netherlands , Niels Bohrweg 4 , 2333CA Leiden , The Netherlands

16. Jonathan Keathley
17. Alexandre de Larminat

    Centre National de la Recherche Scientifique · Institut de physique du globe de Paris · Université Paris Cité

    Affiliation as printed

    Université Paris Cité , Institut de physique du globe de Paris , CNRS , Paris , France

18. Emmanuel Marcq

    Laboratoire atmosphères, milieux, observations spatiales

    Affiliation as printed

    Laboratoire Atmospheres Milieux Observations Spatiales , France

19. Lena Noack

    Freie Universität Berlin

    Affiliation as printed

    Institut für Geologische Wissenschaften , Freie Universität Berlin , Germany

20. Hugo Pelissard
21. Bo Peng
22. Emma Postolec
23. Ramsés Ramírez

    University of Central Florida

    Affiliation as printed

    University of Central Florida , USA

24. Mariana Sastre

    University of Groningen

    Affiliation as printed

    Kapteyn Astronomical Institute , University of Groningen , The Netherlands

25. Andrea Zorzi

    Stanford University

    Affiliation as printed

    Stanford University , USA