Rocky Planets as Heat Engines
Year: 2026
Type: article
Abstract: Rocky planets act as heat engines, using internal heat to drive mantle convection, tectonic activity, crustal evolution and magnetic field generation. This ultimately shapes the surface environment and long-term habitability. This article reviews the physical and chemical processes governing the interior dynamics of rocky planets in the Solar System and beyond, emphasizing how variations in heat sources, material properties, internal structure, and boundary conditions (e.g., surface temperature and stellar flux) lead to diverse evolutionary pathways. Planetary heat arises from primordial accretion, core formation, radiogenic decay, tidal dissipation, and impact heating, and these energy sources regulate convective vigor and heat loss over geological timescales. Depending on different mechanical, thermal, and compositional controls, rocky planets can exhibit a spectrum of tectonic regimes, including plate tectonics, episodic lid, stagnant lid, and plutonic-squishy lid. Particular attention is given to the role of crustal buoyancy, volatile content, rheology, surface temperature, and magmatic intrusion-extrusion balance in governing lithospheric mobility and recycling efficiency. We further review models of coupled thermal and chemical evolution, including magma ocean solidification, mantle differentiation, crust formation, and volatile cycling between the interior and atmosphere. The implications of interior evolution for planetary magnetic fields are discussed, highlighting how mantle cooling histories influence dynamo generation and longevity. Finally, we review the links between tectonic regime, atmospheric evolution, and planetary habitability, with Earth serving as a reference case within a broader comparative planetary framework. By integrating insights from geodynamics, mineral physics, planetary science, and exoplanet observations, this article aims to provide a unifying framework for interpreting the interior state, thermal evolution, and tectonic diversity of rocky exoplanets, and to support future efforts to understand their dynamics, evolution, and potential for habitability.
Source: Space Science Reviews
Institutions: ETH Zurich, Institute of Geophysics, Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR), Lyon 1 Université, École Normale Supérieure de Lyon, Centre National de la Recherche Scientifique, Laboratoire de Géologie de Lyon : Terre, Planètes et Environnement, Freie Universität Berlin, University of Geneva, Washington University in St. Louis, Monash University, Université Côte d'Azur, Géoazur, University of Lisbon, Instituto Dom Luiz, Pennsylvania State University, Yale University, Carnegie Institution for Science, University of Pavia, Earth and Planets Laboratory, The University of Texas at Dallas
Language: English
Topic: Astro and Planetary Science
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $5,290
Awards: G1660133579, Research - Carnegie Institution of Washington (2021), G3438831512, The pulse of the earth, G428507629, Coupled interior-atmosphere evolution of Venus and rocky exoplanets from magma ocean to the present day, Exploring the interactions between the internal structure, the atmosphere and the tidal evolution of planets around low-mass stars, Exploring the interactions between the internal structure, the atmosphere and the tidal evolution of planets around low-mass stars
OpenAlex ID: W7204105819