Exoplanets & Exomoons

Lava Worlds: From Early Earth to Exoplanets

By Keith Cowing
December 14, 2020
Filed under
Lava Worlds: From Early Earth to Exoplanets
Lava world

The magma ocean concept was first conceived to explain the geology of the Moon, but hemispherical or global oceans of silicate melt could be a widespread “lava world” phase of rocky planet accretion, and could persist on planets on short-period orbits around other stars.

The formation and crystallization of magma oceans could be a defining stage in the assembly of a core, origin of a crust, initiation of tectonics, and formation of an atmosphere. The last decade has seen significant advances in our understanding of this phenomenon through analysis of terrestrial and extraterrestrial samples, planetary missions, and astronomical observations of exoplanets.

This review describes the energetic basis of magma oceans and lava worlds and the lava lake analogs available for study on Earth and Io. It provides an overview of evidence for magma oceans throughout the Solar System and considers the factors that control the rocks these magma oceans leave behind. It describes research on theoretical and observed exoplanets that could host extant magma oceans and summarizes efforts to detect and characterize them. It reviews modeling of the evolution of magma oceans as a result of crystallization and evaporation, the interaction with the underlying solid mantle, and the effects of planetary rotation.

The review also considers theoretical investigations on the formation of an atmosphere in concert with the magma ocean and in response to irradiation from the host star, and possible end-states. Finally, it describes needs and gaps in our knowledge and points to future opportunities with new planetary missions and space telescopes to identify and better characterize lava worlds around nearby stars.

Keng-Hsien Chao, Rebecca deGraffenried, Mackenzie Lach, William Nelson, Kelly Truax, Eric Gaidos

Comments: Accepted, invited review for Geochemistry. This entry will be updated with journal reference and DOI when available
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2012.07337 [astro-ph.EP] (or arXiv:2012.07337v1 [astro-ph.EP] for this version)
Submission history
From: Eric Gaidos
[v1] Mon, 14 Dec 2020 08:42:56 UTC (5,484 KB)

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) 🖖🏻