Molecular hydrogen in CO₂-dominated atmospheres of terrestrial exoplanets : impact on the photochemical formation of water

Thomas Drant (1) , Nathalie Carrasco (1) , Zoé Perrin (1) , Ludovic Vettier (1) , S.-M. Tsai (2) , K. Heng (3)

1 PLANETO - LATMOS
2 Department of Physics [Oxford]
3 CSH - Center for Space and Habitability

As for the rocky planets of the Solar System, the atmosphere of terrestrial exoplanets is affected by volcanic outgassing. Significant emissions of molecular hydrogen are expected in the early stage of their evolution. In the upper atmosphere, molecular hydrogen becomes photochemically active along with CO2. Laboratory experiments conducted highlight a significant formation of water which strongly depends on the concentration of molecular hydrogen.

Keywords: atmosphere; terrestrial exoplanet; photochemistry

Domains: Sciences of the Universe [physics]

Thomas Drant, Nathalie Carrasco, Zoé Perrin, Ludovic Vettier, S.-M. Tsai, et al.. Molecular hydrogen in CO₂-dominated atmospheres of terrestrial exoplanets : impact on the photochemical formation of water. SF2A-2021: Proceedings of the Annual meeting of the French Society of Astronomy and Astrophysics, Jun 2021, On Line, France. pp.47-49. ⟨insu-03539911⟩