Airy Worlds Or Barren Rocks? On The Survivability Of Secondary Atmospheres Around The TRAPPIST-1 Planets

By Keith Cowing
Status Report
January 31, 2024
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Airy Worlds Or Barren Rocks? On The Survivability Of Secondary Atmospheres Around The TRAPPIST-1 Planets
TRAPPIST-1 planets and the inner planets f our solar system. — NASA

In this work we aim to determine the atmospheric survivability of the TRAPPIST-1 planets by modelling the response of the upper atmosphere to incoming stellar high-energy radiation.

Through this case study, we also aim to learn more about rocky planet atmospheres in the habitable zone around low-mass M dwarfs. We simulated the upper atmospheres using the Kompot code, a self-consistent thermo-chemical code.

Specifically, we studied the atmospheric mass loss due to Jeans escape induced by stellar high-energy radiation. This was achieved through a grid of models that account for the differences in planetary properties, irradiances, and atmospheric properties, allowing the exploration of the different factors influencing atmospheric loss.

The present-day irradiance of the TRAPPIST-1 planets would lead to the loss of an Earth’s atmosphere within just some 100 Myr. Taking into account the much more active early stages of a low-mass M dwarf, the planets undergo a period of even more extreme mass loss, regardless of planetary mass or atmospheric composition. This indicates that it is unlikely that any significant atmosphere could survive for any extended amount of time around any of the TRAPPIST-1 planets.

The assumptions used here allow us to generalise the results, and we conclude that the results tentatively indicate that this conclusion applies to all Earth-like planets in the habitable zones of low-mass M dwarfs.

Gwenaël Van Looveren, Manuel Güdel, Sudeshna Boro Saikia, Kristina Kislyakova

Comments: Accepted for publication in Astronomy and Astrophysics
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2401.16490 [astro-ph.EP] (or arXiv:2401.16490v1 [astro-ph.EP] for this version)
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Submission history
From: Gwenaël Van Looveren
[v1] Mon, 29 Jan 2024 19:04:07 UTC (2,824 KB)

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻