Abstract

Many super-Earths are very close to their host star and are therefore likely to be tidally locked. Tidally locked super-Earths experience intense solar heating on their permanent dayside, while the nightside surface can reach extremely cold temperatures. In this presentation, I will show how this extreme contrast between the dayside and nightside surface temperature influences the mantle dynamics of rocky super-Earths. I will first discuss the case of super-Earth GJ 486b, for which it is not known whether this planet was able to retain an atmosphere are not. Subsequently, I will present results for super-Earths that experience stellar irradiation high enough to harbour a magma ocean, such as 55 Cancri e or K2-141b. When the planet’s dayside is covered by a thick magma ocean, our simulations reveal the formation of a hot super-plume that ascends towards the magma ocean which could facilitate the recycling of material between the nightside and dayside. Given the undergoing observations of these planets by JWST , understanding the interplay between the planet’s atmosphere, magma ocean, and underlying solid mantle becomes particularly crucial.