magma ocean Archives - Page 4 of 6 - Astrobiology

Outgassed atmospheric composition at model termination for HD 63433 d (top) and TRAPPIST-1 c (bottom), versus mantle 𝑓 O2 (x-axis), simulated with both atmosphere models (y-axis). Pie chars show volatile volume mixing ratios and white numbers show log10 total surface pressure [bar]. -- astro-ph.EP

Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Exoplanets, -moons, -comets, Habitable Zones, Lava / magma ocean / Volcanic Worlds, Status Report, TRAPPIST-1

Convective Shutdown In The Atmospheres of Lava Worlds

by Keith CowingDecember 18, 2024December 18, 2024

Atmospheric energy transport is central to the cooling of primordial magma oceans. Theoretical studies of atmospheres on lava planets have assumed that convection is the only process involved in setting […]

This schematic depicts the set-up of the volatile exchange during initialization (t=0) and run time. For initialization, a surface temperature of 4000 K and a completely molten magma ocean is assumed, where the dissolved volatiles are in balance with the outgassed volatile content, set by the volatile melt fraction Fi . As the magma ocean solidifies, part of the volatile budget is deposited in the solid mantle. Further, atmospheric escape can remove H2O. These two sink terms thus reduce the amount of a volatile available in the fully coupled magma ocean-atmosphere system Mimoa . The full overview of all included processes, including radiogenic heating, is shown in Barth et al. (2021, Fig. 1) -- astro-ph.EP

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

How Mixed Outgassing Changes The Volatile Distribution In Magma Oceans Around M Dwarf Stars

by Keith CowingDecember 17, 2024December 17, 2024

We investigate the impact of CO2 on TRAPPIST-1 e, f and g during the magma ocean stage. These potentially habitable rocky planets are currently the most accessible for astronomical observations.

A schematic illustrating the different planetary models under study. In both models, (A) and (B), the planet has a molten core that contributes negligibly to the tidally dissipated energy (this also stands if the core is differentiated into a solid inner and fluid outer parts). On top of the core lies a viscoelastic solid mantle which can be stratified and further divided into layers of uniform physical properties. Tidal dissipation in this mantle is computed in the solid tidal formalism using ALMA3 (Section 2.1). The solid mantle is enveloped by a fluid magma ocean of unperturbed uniform thickness H, which is the focus of our study. Under tidal forcing of the ocean and the mantle, the ocean’s bottom (top) is displaced vertically by ζ ↓ (ζ ↑ ). This forcing also leads to heating (by virtue of several dissipative mechanisms in reality, but mainly due to friction at the ocean-solid mantle interface, as shown in the sketch). The heating is counteracted by convective cooling. This molten layer can either be the outermost layer of the planet (A), or it can live under a solidified crust (B). -- astro-ph.EP

Astrogeology, Biogeochemical Cycles & Geobiology, Exoplanets, -moons, -comets, Habitable Zones, Lava / magma ocean / Volcanic Worlds, Mapping, Geodesy, Cartography, Bathymetry, Status Report, Venus

Tides on Lava Worlds: Application to Close-in Exoplanets and the Early Earth-Moon System

by Keith CowingDecember 11, 2024December 11, 2024

Understanding the physics of planetary magma oceans has been the subject of growing efforts, in light of the increasing abundance of Solar system samples and extrasolar surveys. A rocky planet […]

This illustration shows the seven Earth-size planets of TRAPPIST-1, an exoplanet system about 40 light-years away, based on data current as of February 2018. The image shows the planets relative sizes but does not represent their orbits to scale. The art highlights possibilities for how the surfaces of these intriguing worlds might look based on their newly-calculated properties. The seven planets of TRAPPIST-1 are all Earth-sized and terrestrial. TRAPPIST-1 is an ultra-cool dwarf star in the constellation Aquarius, and its planets orbit very close to it. Larger image

Astronomy & Telescopes, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Gaia - Planetary Perspectives, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Lava / magma ocean / Volcanic Worlds, Press Release, TRAPPIST-1, Water/Hycean Worlds & Oceanography

Rocky Planets Orbiting Small Stars Could Have Stable Atmospheres Needed To Support Life

by Keith CowingOctober 25, 2024October 25, 2024

Since its launch in late 2021, NASA’s James Webb Space Telescope has raised the possibility that we could detect signs of life on exoplanets, or planets outside our solar system.

Schematic of the 1D thermal evolution model used in this work. 𝑄𝑅 is the radiated flux, 𝑄𝑀𝑂 is the heat flux from the magma ocean, 𝑄𝑀𝑆 the heat flux from the magma mush, 𝑄𝑆 the flux from solid rock and 𝑄𝑐 the flux from the core. 𝑄𝐻 is the heat removed from the day-side and added to the night-side when we include horizontal heat transport. 𝑄𝑇 is the tidal heating when tidal dissipation is included in the model. The light blue line is the geotherm of the mantle while the line "L" (dark blue line) is the mantle liquidus and "S" (green line) is the mantle solidus. The pressure increases in the downward direction while the temperature increases to the right. -- astro-ph.EP

Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Habitable Zones, Lava / magma ocean / Volcanic Worlds, Status Report, Water/Hycean Worlds & Oceanography

Thermal Evolution Of Lava Planets

by Keith CowingSeptember 20, 2024September 20, 2024

Rocky planets are thought to form with a magma ocean that quickly solidifies. The horizontal and vertical extent of this magma ocean depends on the interior thermal evolution of the […]

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Lava / magma ocean / Volcanic Worlds, Status Report

Self-oxidation of the Atmospheres of Rocky Planets with Implications for the Origin of Life

by Keith CowingSeptember 18, 2024September 18, 2024

Rocky planets may acquire a primordial atmosphere by outgassing of volatiles from their magma ocean. The distribution of O between H2O, CO and CO2 in chemical equilibrium subsequently changes significantly […]

Upper panels: The peak hydrogen envelope mass fraction at the end of accretion, before any mass loss, shown in colour for the slow, medium and fast host star rotators. The time when 90% of the envelope mass is lost due to solar XUV radiation is shown in white contour lines in Myr. Lower panels: The atomic composition of the outgassed atmospheres of the slow, medium and fast rotator simulations at 300 Myr. Values of R/O < 1 (blue) indicate an atmosphere with free oxygen, a value of R/O=1 (green) imply sufficient oxygen to oxidise H to H2O and C to CO2, and values of R/O > 1 (red) indicate reducing conditions (see definition of R/O in equation 8). The white contour lines in the lower panels show a value of R/O = 1.3. The patch of R/O=0 present for the slow rotator is due to the perseverance of the envelope for those high planetary masses even after 300 Myr, with the magma ocean still providing a significant pressure of free oxygen. -- astro-ph.EP

Astrochemistry, Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Exoplanets, -moons, -comets, Habitable Zones, Lava / magma ocean / Volcanic Worlds, Meteorites & Asteroids, Status Report, Water/Hycean Worlds & Oceanography

Evolution of Gas Envelopes and Outgassed Atmospheres of Rocky Planets Formed via Pebble Accretion

by Keith CowingSeptember 18, 2024September 18, 2024

We present here results of numerical simulations of the formation and early evolution of rocky planets through pebble accretion, with an with an emphasis on hydrogen envelope longevity and the […]

LP 791-18 d, shown here in an artist’s concept, is an Earth-size world about 90 light-years away. The gravitational tug from a more massive planet in the system, shown as a blue disk in the background, may result in internal heating and volcanic eruptions – as much as Jupiter’s moon Io, the most geologically active body in the solar system. Astronomers discovered and studied the planet using data from NASA’s Spitzer Space Telescope and TESS (Transiting Exoplanet Survey Satellite) along with many other observatories. Credit: NASA’s Goddard Space Flight Center/Chris Smith (KRBwyle)

Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Gaia - Planetary Perspectives, Habitable Zones, Lava / magma ocean / Volcanic Worlds, Status Report

Thermal and Magnetic Evolution Of An Earth-like Planet With A Basal Magma Ocean

by Keith CowingSeptember 11, 2024

Earth’s geodynamo has operated for over 3.5 billion years. The magnetic field is currently powered by thermocompositional convection in the outer core, which involves the release of light elements and […]

The schematic figure of the vertical structure of the sub-Neptune model presented in this study. The black line within the atmosphere layer illustrates the assumed temperature-pressure relationship in our model. Chemical species involved in internal reactions are written in red within each structural layer. The RCB stands for the Radiative-Convective Boundary, while the BOA denotes the Bottom of the Atmosphere -- astro-ph.EP

Astrogeology, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Habitable Zones, Lava / magma ocean / Volcanic Worlds, Status Report

Role of Magma Oceans in Controlling Carbon and Oxygen of Sub-Neptune atmospheres

by Keith CowingSeptember 3, 2024September 3, 2024

Most exoplanets with a few Earth radii are more inflated than bare-rock planets with the same mass, indicating a substantial volatile amount. Neither the origin of the volatiles nor the […]

Closed diamonds: this study (pyrolite composition at fO2 = IW + 2.0), including ±50 °C uncertainties (described in the note of Table 1); open diamonds: Ishii et al.19 (minimum solidus temperatures, indicated by the red arrows, for a pyrolite composition at estimated IW − 1.2); open circles: Herzberg et al.17 (KLB-1 peridotite composition, estimated IW − 1.2); open squares: Andrault et al.20 (chondritic mantle composition, oxygen fugacity not determined but more oxidized than IW − 1.2); crosses: Pierru et al.22 (pyrolitic mantle composition, oxygen fugacity estimated to be about IW + 2). All data are presented as mean values with ± standard errors (the latter when provided by the authors; Source Data Fig. 1). Dashed lines show predicted solidi at fO2 conditions invoked in siderophile element-based core formation models (IW − 1, IW − 2 and IW − 4), predicted based on equation (1). -- Okayama University

Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Habitable Zones, Lava / magma ocean / Volcanic Worlds, Press Release, Water/Hycean Worlds & Oceanography

Uncovering The Role Of Oxygen Concentration In The Formation Of Early Earth Magma Ocean

by Keith CowingAugust 28, 2024August 27, 2024

It is widely accepted that the early Earth largely consisted of molten magma, forming a global ocean of magma. This extreme state of Earth was likely caused by the intense […]