Atmospheric Collapse and Habitability on Tidally-Locked Exoplanets

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Taniguchi, Keigo, Kodama, Takanori, Turbet, Martin, Chaverot, Guillaume, Millour, Ehouarn, Genda, Hidenori
Natura: Preprint
Pubblicazione: 2026
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866911501504217088
author Taniguchi, Keigo
Kodama, Takanori
Turbet, Martin
Chaverot, Guillaume
Millour, Ehouarn
Genda, Hidenori
author_facet Taniguchi, Keigo
Kodama, Takanori
Turbet, Martin
Chaverot, Guillaume
Millour, Ehouarn
Genda, Hidenori
contents The habitability of terrestrial exoplanets orbiting M dwarfs is a key topic in the search for extraterrestrial life. The climates of these planets differ significantly from the Earth's due to their likely tidal locking, resulting in a hotter dayside and a colder nightside caused by uneven stellar irradiation. On tidally-locked planets around the outer edge of the habitable zone (HZ), although the definition of the classical HZ requires thick CO2 atmosphere, CO2 can condense onto the surface, leading to the reduction of greenhouse effect. However, the dayside permanent stellar irradiation could maintain a surface liquid water area. The onset of atmospheric collapse and the persistence of surface liquid water are governed by global heat redistribution which is influenced by factors such as atmospheric mass, stellar irradiation, and greenhouse effects. In this study, we used a three-dimensional global climate model to investigate the impact of atmospheric collapse on the presence of dayside surface liquid water. Our results indicate that surface liquid water could counter-intuitively persist despite atmospheric collapse. This is because the loss of atmospheric CO2 weakens not only the greenhouse effect but also daynight heat transport, leading to less redistribution of the energy of dayside insolation to the nightside. While atmospheric collapse is typically seen as an obstacle to maintaining a habitable climate, our findings suggest that it could play a positive role in sustaining surface liquid water on tidally-locked planets. Our work provides new light into the relationship between atmospheric collapse and planetary habitability.
format Preprint
id arxiv_https___arxiv_org_abs_2603_09260
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Atmospheric Collapse and Habitability on Tidally-Locked Exoplanets
Taniguchi, Keigo
Kodama, Takanori
Turbet, Martin
Chaverot, Guillaume
Millour, Ehouarn
Genda, Hidenori
Earth and Planetary Astrophysics
The habitability of terrestrial exoplanets orbiting M dwarfs is a key topic in the search for extraterrestrial life. The climates of these planets differ significantly from the Earth's due to their likely tidal locking, resulting in a hotter dayside and a colder nightside caused by uneven stellar irradiation. On tidally-locked planets around the outer edge of the habitable zone (HZ), although the definition of the classical HZ requires thick CO2 atmosphere, CO2 can condense onto the surface, leading to the reduction of greenhouse effect. However, the dayside permanent stellar irradiation could maintain a surface liquid water area. The onset of atmospheric collapse and the persistence of surface liquid water are governed by global heat redistribution which is influenced by factors such as atmospheric mass, stellar irradiation, and greenhouse effects. In this study, we used a three-dimensional global climate model to investigate the impact of atmospheric collapse on the presence of dayside surface liquid water. Our results indicate that surface liquid water could counter-intuitively persist despite atmospheric collapse. This is because the loss of atmospheric CO2 weakens not only the greenhouse effect but also daynight heat transport, leading to less redistribution of the energy of dayside insolation to the nightside. While atmospheric collapse is typically seen as an obstacle to maintaining a habitable climate, our findings suggest that it could play a positive role in sustaining surface liquid water on tidally-locked planets. Our work provides new light into the relationship between atmospheric collapse and planetary habitability.
title Atmospheric Collapse and Habitability on Tidally-Locked Exoplanets
topic Earth and Planetary Astrophysics
url https://arxiv.org/abs/2603.09260