Most Super-Earths Have Less Than 3% Water
Super-Earths are highly irradiated, small planets with bulk densities approximately consistent with Earth. We construct combined interior atmosphere models of super-Earths that trace the partitioning of water throughout a planet, including an iron-rich core, silicate-rich mantle, and steam atmospher...
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| Format: | Article |
| Language: | English |
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IOP Publishing
2025-01-01
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| Series: | The Astrophysical Journal |
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| Online Access: | https://doi.org/10.3847/1538-4357/ad9f61 |
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| author | James G. Rogers Caroline Dorn Vivasvaan Aditya Raj Hilke E. Schlichting Edward D. Young |
| author_facet | James G. Rogers Caroline Dorn Vivasvaan Aditya Raj Hilke E. Schlichting Edward D. Young |
| author_sort | James G. Rogers |
| collection | DOAJ |
| description | Super-Earths are highly irradiated, small planets with bulk densities approximately consistent with Earth. We construct combined interior atmosphere models of super-Earths that trace the partitioning of water throughout a planet, including an iron-rich core, silicate-rich mantle, and steam atmosphere. We compare these models with exoplanet observations to infer a 1 σ upper limit on the total water mass fraction of ≲3% at the population level. We consider end-member scenarios that may change this value, including the efficiency of mantle outgassing, escape of high mean molecular weight atmospheres, and increased iron core mass fractions. Although our constraints are agnostic as to the origin of water, we show that our upper limits are consistent with its production via chemical reactions of primordial hydrogen-dominated atmospheres with magma oceans. This mechanism has also been hypothesised to explain Earth's water content, possibly pointing to a unified channel for the origins of water on small terrestrial planets. |
| format | Article |
| id | doaj-art-53f13e0cabff47c4b54936ab9c5e748b |
| institution | Kabale University |
| issn | 1538-4357 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj-art-53f13e0cabff47c4b54936ab9c5e748b2025-01-20T09:35:43ZengIOP PublishingThe Astrophysical Journal1538-43572025-01-0197917910.3847/1538-4357/ad9f61Most Super-Earths Have Less Than 3% WaterJames G. Rogers0https://orcid.org/0000-0001-7615-6798Caroline Dorn1https://orcid.org/0000-0001-6110-4610Vivasvaan Aditya Raj2https://orcid.org/0009-0004-7590-3818Hilke E. Schlichting3https://orcid.org/0000-0002-0298-8089Edward D. Young4https://orcid.org/0000-0002-1299-0801Institute of Astronomy, University of Cambridge , Madingley Road, Cambridge CB3 0HA, UK; Department of Earth, Planetary, and Space Sciences, The University of California, Los Angeles , 595 Charles E. Young Drive East, Los Angeles, CA 90095, USAInstitute for Particle Physics and Astrophysics , ETH Zurich Department of Physics, Wolfgang-Pauli-Strasse 27, CH-8093 Zurich, SwitzerlandDepartment of Earth, Planetary, and Space Sciences, The University of California, Los Angeles , 595 Charles E. Young Drive East, Los Angeles, CA 90095, USADepartment of Earth, Planetary, and Space Sciences, The University of California, Los Angeles , 595 Charles E. Young Drive East, Los Angeles, CA 90095, USADepartment of Earth, Planetary, and Space Sciences, The University of California, Los Angeles , 595 Charles E. Young Drive East, Los Angeles, CA 90095, USASuper-Earths are highly irradiated, small planets with bulk densities approximately consistent with Earth. We construct combined interior atmosphere models of super-Earths that trace the partitioning of water throughout a planet, including an iron-rich core, silicate-rich mantle, and steam atmosphere. We compare these models with exoplanet observations to infer a 1 σ upper limit on the total water mass fraction of ≲3% at the population level. We consider end-member scenarios that may change this value, including the efficiency of mantle outgassing, escape of high mean molecular weight atmospheres, and increased iron core mass fractions. Although our constraints are agnostic as to the origin of water, we show that our upper limits are consistent with its production via chemical reactions of primordial hydrogen-dominated atmospheres with magma oceans. This mechanism has also been hypothesised to explain Earth's water content, possibly pointing to a unified channel for the origins of water on small terrestrial planets.https://doi.org/10.3847/1538-4357/ad9f61Exoplanet structureExoplanetsExoplanet formationExoplanet evolution |
| spellingShingle | James G. Rogers Caroline Dorn Vivasvaan Aditya Raj Hilke E. Schlichting Edward D. Young Most Super-Earths Have Less Than 3% Water The Astrophysical Journal Exoplanet structure Exoplanets Exoplanet formation Exoplanet evolution |
| title | Most Super-Earths Have Less Than 3% Water |
| title_full | Most Super-Earths Have Less Than 3% Water |
| title_fullStr | Most Super-Earths Have Less Than 3% Water |
| title_full_unstemmed | Most Super-Earths Have Less Than 3% Water |
| title_short | Most Super-Earths Have Less Than 3% Water |
| title_sort | most super earths have less than 3 water |
| topic | Exoplanet structure Exoplanets Exoplanet formation Exoplanet evolution |
| url | https://doi.org/10.3847/1538-4357/ad9f61 |
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