Habitability of Tidally Heated H$_2$-Dominated Exomoons around Free-Floating Planets
Fuente:
arXiv
Enregistré dans:
| Auteurs principaux: | , , , , , , |
|---|---|
| Format: | Preprint |
| Publié: |
2026
|
| Sujets: | |
| Accès en ligne: | |
| Tags: |
Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
|
| _version_ | 1866908815367077888 |
|---|---|
| author | Dahlbüdding, David Grassi, Tommaso Molaverdikhani, Karan Roccetti, Giulia Ercolano, Barbara Braun, Dieter Caselli, Paola |
| author_facet | Dahlbüdding, David Grassi, Tommaso Molaverdikhani, Karan Roccetti, Giulia Ercolano, Barbara Braun, Dieter Caselli, Paola |
| contents | Exomoons around free-floating planets (FFPs) can survive their host planet's ejection. Such ejections can increase their orbital eccentricity, providing significant tidal heating in the absence of any stellar energy source. Previous studies suggested that liquid water could exist on such moons under thick CO$_2$-dominated atmospheres, but these models faced challenges with CO$_2$ condensation and atmospheric collapse, particularly in the high-pressure regimes that favoured long-term habitability. To address this, we employ a self-consistent model, including radiative transfer and equilibrium chemistry with condensation, to simulate a more stable hydrogen-dominated atmosphere for a range of initial chemical compositions, including C, O, and N. We find that such atmospheres can effectively trap heat via collision-induced absorption of H$_2$, maintaining surface temperatures suitable for liquid water for time-scales of up to 4.3 Gyr, depending on the surface pressure, while not prone to condensation-induced collapse. Wet-dry cycling caused by the strong tides together with the alkalinity of dissolved NH$_3$ could create favourable conditions for RNA polymerisation and thus support the emergence of life. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2602_05378 |
| institution | arXiv |
| publishDate | 2026 |
| record_format | arxiv |
| spellingShingle | Habitability of Tidally Heated H$_2$-Dominated Exomoons around Free-Floating Planets Dahlbüdding, David Grassi, Tommaso Molaverdikhani, Karan Roccetti, Giulia Ercolano, Barbara Braun, Dieter Caselli, Paola Earth and Planetary Astrophysics Exomoons around free-floating planets (FFPs) can survive their host planet's ejection. Such ejections can increase their orbital eccentricity, providing significant tidal heating in the absence of any stellar energy source. Previous studies suggested that liquid water could exist on such moons under thick CO$_2$-dominated atmospheres, but these models faced challenges with CO$_2$ condensation and atmospheric collapse, particularly in the high-pressure regimes that favoured long-term habitability. To address this, we employ a self-consistent model, including radiative transfer and equilibrium chemistry with condensation, to simulate a more stable hydrogen-dominated atmosphere for a range of initial chemical compositions, including C, O, and N. We find that such atmospheres can effectively trap heat via collision-induced absorption of H$_2$, maintaining surface temperatures suitable for liquid water for time-scales of up to 4.3 Gyr, depending on the surface pressure, while not prone to condensation-induced collapse. Wet-dry cycling caused by the strong tides together with the alkalinity of dissolved NH$_3$ could create favourable conditions for RNA polymerisation and thus support the emergence of life. |
| title | Habitability of Tidally Heated H$_2$-Dominated Exomoons around Free-Floating Planets |
| topic | Earth and Planetary Astrophysics |
| url | https://arxiv.org/abs/2602.05378 |