Planetary bodies classified as lava worlds are terrestrial exoplanets situated in such proximate orbits to their parent stars that their sun-facing hemispheres attain temperatures sufficient to liquefy silicate minerals.
Boukaré et al. introduce a simple theoretical framework to describe the evolution of the coupled interior-atmosphere system of lava planets. Image credit: Sci.News.
Lava planets encompass celestial bodies ranging in size from Earth-like to super-Earth, which traverse orbits extremely near their host stars, completing a full revolution in under one Earth day.
It is widely theorized that, akin to Earth’s Moon, these planets are tidally locked, perpetually presenting a single side to their stellar companion.
The thermal conditions on their dayside exteriors escalate to such an extreme that silicate rocks undergo liquefaction and even volatilization, engendering environments starkly dissimilar to any encountered within our Solar System.
These exceptionally peculiar celestial entities, readily detectable due to their remarkably brief orbital durations, furnish unparalleled insights into the fundamental mechanisms governing planetary metamorphosis.
“The orbital configurations of lava planets are so extreme that our established understanding of rocky planets within the Solar System is not directly applicable, leaving scientists uncertain about the phenomena to anticipate when observing them,” stated Dr. Charles-Édouard Boukaré, a researcher affiliated with York University.
“Our simulations posit a conceptual architecture for comprehending their developmental trajectories and offer potential scenarios for investigating their internal dynamics and chemical transformations over extended periods.”
“While these processes are significantly accentuated on lava planets, they are fundamentally analogous to those that sculpt terrestrial planets within our indigenous Solar System.”
Upon the melting or vaporization of rocks, constituent elements such as magnesium, iron, silicon, oxygen, sodium, and potassium exhibit differential partitioning between gaseous, liquid, and solid phases.
The distinctive orbital arrangement of lava planets sustains vapor-liquid and solid-liquid equilibrium for durations spanning billions of years, thereby propelling long-term geochemical evolution.
Leveraging advanced numerical simulations, the research team has predicted two distinct terminal evolutionary states:
(i) A completely molten interior (characteristic of nascent planets): the atmospheric composition mirrors that of the planet’s bulk, and internal heat transfer maintains a heated and active nightside surface;
(ii) A predominantly solid interior (indicative of more mature planets): a superficial molten rock layer persists on the dayside, and the atmosphere becomes depleted of elements like sodium, potassium, and iron.
“We harbor a strong aspiration that the NASA/ESA/CSA James Webb Space Telescope will enable us to observe and differentiate between ancient and young lava planets,” Dr. Boukaré conveyed.
“Should we achieve this capability, it would represent a significant advancement in transcending the conventional, static perspective of exoplanets.”
This groundbreaking investigation has been formally published today in the esteemed journal Nature Astronomy.
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CÉ. Boukaré et al. The role of interior dynamics and differentiation on the surface and in the atmosphere of lava planets. Nat Astron, published online July 29, 2025; doi: 10.1038/s41550-025-02617-4
