Exoplanets, -moons, -comets

Fundamentals Of Interior Modelling And Challenges In The Interpretation Of Observed Rocky Exoplanets

By Keith Cowing
Status Report
astro-ph.EP
January 14, 2026
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Fundamentals Of Interior Modelling And Challenges In The Interpretation Of Observed Rocky Exoplanets
Pressure-temperature diagrams illustrating the ranges covered by the available experimental techniques along with some references for solar system planets and exoplanets. The figure on the right is modified from Duffy and Smith (2019). – -astro-ph.EP

Most our knowledge about rocky exoplanets is based on their measure of mass and radius. These two parameters are routinely measured and are used to categorise different populations of observed exoplanets.

They are also tightly linked to the planet’s properties, in particular those of the interior. As such they offer the unique opportunity to interpret the observations and potentially infer the planet’s chemistry and structure. Required for the interpretation are models of planetary interiors, calculated a priori, constrained using other available data, and based on the physiochemical properties of mineralogical phases.

This article offers an overview of the current knowledge about exoplanet interiors, the fundamental aspects and tools for interior modelling and how to improve the contraints on the models, along with a discussion on the sources of uncertainty. The origin and fate of volatiles, and their role in planetary evolution is discussed.

The chemistry and structure of planetary interiors have a pivotal role in the thermal evolution of planets and the development of large scale properties that might become observables with future space missions and ground-based surveys. As such, having reliable and well constrained interior models is of the utmost importance for the advancement of the field.

Philipp Baumeister, Francesca Miozzi, Claire Marie Guimond, Marie-Luise Steinmeyer, Caroline Dorn, Shun-Ichiro Karato, Emeline Bolmont, Alexandre Revol, Alexander Thamm, Lena Noack

Comments: 58 pages, 9 figures, 1 table. Accepted for publication in Space Science Reviews
Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Geophysics (physics.geo-ph)
Cite as: arXiv:2511.10269 [astro-ph.EP](or arXiv:2511.10269v1 [astro-ph.EP] for this version)
https://doi.org/10.48550/arXiv.2511.10269
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Submission history
From: Philipp Baumeister
[v1] Thu, 13 Nov 2025 12:53:41 UTC (5,526 KB)
https://arxiv.org/abs/2511.10269

Astrobiology,

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻