Habitable Zones & Global Climate

Salty Ice And The Dilemma Of Ocean Exoplanet Habitability

By Keith Cowing
astro-ph.EP
July 19, 2022
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Salty Ice And The Dilemma Of Ocean Exoplanet Habitability
Schematic interior structure, dynamic and solute transport and cycling processes inside an ocean superEarth and an icy moon of our solar system with high-pressure ice (Titan, Ganymede and Callisto). Basal melt enriched in solutes and nutrients at the base of the high-pressure ice mantle can be generated by various geological processes like hydrothermal sources, mineral aqueous alteration or volcanic activity. Vertical transport processes like buoyant liquid migration, salty high-pressure (HP) ice thermal plumes, solid-state convection and freezing at the bottom of the ocean into salty HP ice are reported. Possible trapping mechanisms like the formation of stable solute-rich phase reservoir within the HP ice mantle are also illustrated. The thermodynamic and chemical equilibration of the ocean with the atmosphere could lead to atmospheric spectral signatures linked to the ocean composition, detectable by modern and next generation telescopes like the JWST. For icy moons, geophysical and surface signature of the ocean composition will be investigated by upcoming planetary robotic mission ESA JUICE, NASA DragonFly. Background of icy moon Ganymede (NASA/Galileo); Ocean Exoplanet texture generated with PlanetMaker (<a href="http://planetmaker.apoapsys.com/">http://planetmaker.apoapsys.com/</a>).

Habitability of exoplanet’s deepest oceans could be limited by the presence of high-pressure ices at their base.

New work demonstrates that efficient chemical transport within deep planetary ice mantles is possible through significant salt incorporation within the high-pressure ice.

Baptiste Journaux

Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Atmospheric and Oceanic Physics (physics.ao-ph)
Cite as: arXiv:2207.09351 [astro-ph.EP] (or arXiv:2207.09351v1 [astro-ph.EP] for this version)
https://doi.org/10.48550/arXiv.2207.09351
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Journal reference: Nature Communications volume 13, Article number: 3304 (2022)
Related DOI:
https://doi.org/10.1038/s41467-022-30799-2
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Submission history
From: Baptiste Journaux
[v1] Tue, 19 Jul 2022 15:59:14 UTC (1,060 KB)
https://arxiv.org/abs/2207.09351
Astrobiology,

SpaceRef co-founder, Explorers Club Fellow, ex-NASA, Away Teams, Journalist, Space & Astrobiology, Lapsed climber.