magma ocean Archives

Coupled Evolution Of Earth’s H2-rich Proto-atmosphere And Oxidized Magma Ocean

by Keith CowingOctober 31, 2026October 31, 2026

[astro-ph.EP] Giant impacts during Earth’s final accretion likely generated global magma oceans, where the disproportionation of Fe2+ at lower-mantle pressures and segregation of the resulting metallic iron into the core […]

Lava / magma ocean / Volcanic Worlds

Thermal Evolution of Lava Planets Across System Ages: Predictions for Hell of a Survey

by Keith CowingSeptember 27, 2026September 27, 2026

[astro-ph.EP] Ultra-short-period (USP) rocky exoplanets can have dayside temperatures high enough to maintain permanent magma oceans, sitting at the intersection of interior geophysics and atmospheric chemistry. Coupled feedbacks between the […]

Schematic of the three atmospheric retention and loss regimes for close-in rocky planets.

Exoplanets, -moons, -comets

An Evolving Cosmic Shoreline and Sandbar Bounding the Rocky Airless Valley

by Keith CowingAugust 27, 2026August 27, 2026

[astro-ph.EP] Recent JWST observations challenge the traditional ‘cosmic shoreline’ from both sides, revealing thick volatile atmospheres on the hottest close-in ‘lava worlds,’ where irradiation should drive the most extreme escape, […]

Schematic of the coupled interior-atmosphere evolutionary framework PROTEUS, showing the links between interior, surface, atmosphere, and stellar modules. Core components include SPIDER (mantle dynamics), CALLIOPE (surface in-/outgassing), AGNI/JANUS (radiativeand prescribed-convective atmospheres), ZEPHYRUS (atmospheric escape), and MORS (XUV stellar evolution). Modules exchange energy fluxes at each planetary interfaces—including core cooling, volatile outgassing, heat transport, heat loss to space, escape and stellar irradiation—while C–H–O–N–S volatiles are tracked throughout the mantle and atmosphere. -- [astro-ph.EP]

Atmospheres, Climate, Weather

Atmospheric Evolution Through Outgassing And Escape On Young Molten Rocky Exoplanets

by Keith CowingJuly 18, 2026July 18, 2026

[astro-ph.EP] The earliest rocky planet atmospheres are shaped by competition between initial volatile inventories and atmospheric escape. On young magma ocean planets, outgassing competes with atmospheric escape, controlling volatile retention […]

Reflation events (red) occur across a range of ages and with different magnitudes across the evolution of irradiated super-Earths. The plot shows the normalised bulk density evolution of individual simulations, versus the time elapsed since planet formation. The red lines indicate cases where a reflation event occurs, while blue lines indicate those where it does not occur. The evolution tracks that end with a dot indicate the planet has reached an airless state and complete atmospheric erosion by hydrodynamic escape has taken place. The evolution of the two select cases for Figure 1 are highlighted and denoted with a R and D. These cases illustrate in more detail a representative reflation (red) and deflation case (blue). -- [astro-ph.EP]

Astrogeology

Reflation: Redox-driven Atmospheric Inflation As Tracer Of Super-Earth Geochemistry

by Keith CowingJuly 17, 2026July 17, 2026

[astro-ph.EP] We demonstrate that the redox-sensitivity of mantle outgassing can trigger transient episodes of atmospheric re-inflation in highly irradiated and geochemically-reduced super-Earths, a mechanism we term reflation.

Models for Neptune and Uranus derived in this study expressed as density versus radius. Contour colors show density. Key elements of the models are labelled. The bright narrow band at the base of the envelope in each case is the boundary region stable against convection, ∼ 120 km and ∼ 180 km wide in the cases of Neptune and Uranus, respectively. -- astro-ph.EP

Astrogeology, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Ice Giant, Lava / magma ocean / Volcanic Worlds, Neptune, Status Report, Uranus, Water/Hycean Worlds & Oceanography

Ice Giants Revisited: Uranus And Neptune As Magma Ocean Worlds

by Keith CowingJune 18, 2026June 18, 2026

Uranus and Neptune are commonly interpreted as volatile-rich “ice giants”, an assumption that underpins most interior models.

Schematic diagram of the domain (not to scale). The red line represents the outer boundary of the core; the blue line is the outer boundary of the BMO. (a) 𝑥–𝑧 (meridional) plane. The 𝑧 axis is Earth’s rotation axis and normal to the orbital plane. (b) 𝑥–𝑦 (orbital and equatorial) plane. The blue BMO ellipse always has its long axis aligned with the Moon, but the long axis of the red CMB ellipse can have a non-zero phase lag 𝛥𝜙 relative to the Moon. Throughout the main text, we assume that the solid mantle is static, in which case the BMO outer boundary is undeformed; we consider its deformation in appendix D. -- astro-ph.EP

Astrogeology, Lava / magma ocean / Volcanic Worlds, Moon, Origin & Evolution of Life, Status Report

Resonant Lunar Tides Of Earth’s Core And Basal Magma Ocean

by Keith CowingJune 16, 2026June 16, 2026

Earth’s magnetic field is generated by fluid motion in the liquid-metal core and has been active for billions of year.

Kernel density estimates of the bulk elemental mass fractions of the initial planet population. The population is separated into planets that formed inside and outside the water ice line. Planets formed outside the ice line exhibit systematically higher oxygen and hydrogen mass fractions, reflecting enhanced accretion of volatile-rich material, which in turn leads to a relative depletion of refractory elements such as magnesium, iron, sulfur, and silicon. High bulk nitrogen and carbon abundances are exclusively associated with planets that formed outside the ice line. -- astro-ph.EP

Astrochemistry, Astrogeology, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report, Water/Hycean Worlds & Oceanography

The Role of Formation Location in Shaping Sulfur-, Nitrogen-, and Carbon-Bearing Species in Super-Earth and Sub-Neptune Atmospheres

by Keith CowingMay 17, 2026May 17, 2026

Atmospheric compositions of sub-Neptunes and super-Earths are often interpreted as tracers of formation location relative to volatile ice lines.

Schematics of the MELTYQ coupled magma-atmosphere retrieval. The model is valid for sub-Neptune hosting a thick H2-rich atmosphere with enough surface temperature to melt rocks. The model splits the planet in three regions: a rocky core, a deep atmosphere, and an upper atmosphere. The chemistry is coupled allowing to retrieve the composition of the rocky magma via it’s influence on the observable atmosphere. -- astro-ph.EP

Astrogeology, Astronomy & Telescopes, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Exoplanets, -moons, -comets, Lava / magma ocean / Volcanic Worlds, Status Report

Coupling Magma-ocean And Atmospheres In Spectral Retrievals Of Sub-Neptunes

by Keith CowingMay 14, 2026May 14, 2026

Recent high-precision atmospheric observations with JWST is enabling detailed characterization of sub-Neptune atmospheres and motivating efforts to understand and constrain their interiors.

Sensitivity of the Fe anomaly of the overturned silicate layer with respect to the rest of the mantle. (a) Sensitivity of this anomaly vs. mantle thickness. Mars and Earth sizes are represented for clarity. Note that the final anomaly is expected to be maximum when the thickness of the mantle is that of the critical Rayleigh number DRac and tends to 0 at infinite thickness. (b) Sensitivity of the Fe# anomaly vs. the bulk Fe# of the mantle. Earth and Mars compositions are represented for clarity. We extend compositions to lower bulk Fe# than Earth according to (R. J. Spaargaren et al. 2023) (dotted line, see text). All other properties remain fixed at Earth-like values except for gravity acceleration which is scaled linearly to planet size (assumed to be proportional to mantle thickness). The density anomaly secondary axis is valid for both, panel (a) and (b). -- astro-ph.EP

Astrogeology, Biogeochemical Cycles & Geobiology, Mapping, Geodesy, Cartography, Bathymetry, Mars, Press Release

Earth And Mars Interior Structures Set By Re-melting Of The First Solid Mantle

by Keith CowingMay 8, 2026May 8, 2026

Magma ocean crystallisation sets up the early structure and long-term evolution of terrestrial planets. Recent seismic evidence signals the presence of a silicate layer at the base of Mars’ mantle.