Issue |
A&A
Volume 699, July 2025
|
|
---|---|---|
Article Number | A67 | |
Number of page(s) | 14 | |
Section | Planets, planetary systems, and small bodies | |
DOI | https://doi.org/10.1051/0004-6361/202453069 | |
Published online | 01 July 2025 |
The atmospheres of rocky exoplanets
III. Using atmospheric spectra to constrain surface rock composition
Institute for Astronomy (IfA), University of Vienna,
Türkenschanzstrasse 17,
1180
Vienna,
Austria
★ Corresponding author: oliver.herbort@univie.ac.at
Received:
19
November
2024
Accepted:
12
May
2025
Context. The crust composition of rocky exoplanets with substantial atmospheres cannot be observed directly. However, recent developments have enabled novel observations and characterisations of their atmospheres.
Aims. We aim to establish a link between observable spectroscopic atmospheric features and the mineralogical crust composition of exoplanets. This enables us to constrain the surface composition simply by observing the transit spectra.
Methods. We used a diverse set of total element abundances inspired by various rock compositions, Earth, Venus, and CI chondrite as a basis for our bottom-to-top atmospheric model. We assumed thermal and chemical equilibrium between the atmosphere and the planetary surface. Based on the atmospheric models in hydrostatic and chemical equilibrium, with the inclusion of element depletion due to cloud formation, we calculated the theoretical transit spectra.
Results. The atmospheric type classification allows us to constrain the surface mineralogy, especially with respect to sulphur compounds, iron oxides and hydroxides, feldspars, silicates, and carbon species. Spectral features offer an opportunity to differentiate among the atmospheric types, allowing for a number of constraints to be placed on the surface composition.
Key words: astrochemistry / planets and satellites: atmospheres / planets and satellites: composition / planets and satellites: surfaces / planets and satellites: terrestrial planets
© The Authors 2025
Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
This article is published in open access under the Subscribe to Open model. Subscribe to A&A to support open access publication.
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.