Habitable Zones & Global Climate

Tidal Evolution Of Earth-like Planets In The Habitable Zone Of Low-mass Stars

By Keith Cowing
Status Report
astro-ph.EP
October 2, 2024
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Tidal Evolution Of Earth-like Planets In The Habitable Zone Of Low-mass Stars
Earthlike planet orbiting a M Dwarf star — NASA

Earth-like planets in the habitable zone of low-mass stars undergo strong tidal effects that modify their spin states.

These planets are expected to host dense atmospheres that can also play an important role in the spin evolution. On one hand, gravitational tides tend to synchronise the rotation with the orbital mean motion, but on the other hand, thermal atmospheric tides push the rotation away and may lead to asynchronous equilibria.

Here, we investigate the complete tidal evolution of Earth-like planets by taking into account the effect of obliquity and eccentric orbits. We adopted an Andrade rheology for the gravitational tides and benchmarked the unknown parameters with the present rotation of Venus.

We then applied our model to Earth-like planets, and we show that asynchronous rotation can be expected for planets orbiting stars with masses between 0.4 and 0.9 M and semi-major axes between 0.2 and 0.7 au.

Interestingly, we find that Earth-like planets in the habitable zone of stars with masses ∼0.8 M may end up with an equilibrium rotation of 24 hours. We additionally find that these planets can also develop high obliquities, which may help sustain temperate environments.

E. F. S. Valente, A. C. M. Correia, P. Auclair-Desrotour, M. Farhat, J. Laskar

Comments: 15 pages, 11 figures, 2 tables
Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Atmospheric and Oceanic Physics (physics.ao-ph)
Cite as: arXiv:2410.00739 [astro-ph.EP] (or arXiv:2410.00739v1 [astro-ph.EP] for this version)
https://doi.org/10.48550/arXiv.2410.00739
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Journal reference: Astronomy and Astrophysics, vol. 687, A47 (2024)
Related DOI:
https://doi.org/10.1051/0004-6361/202348450
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Submission history
From: Alexandre Correia
[v1] Tue, 1 Oct 2024 14:29:07 UTC (1,153 KB)
https://arxiv.org/abs/2410.00739

Astrobiology,

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) 🖖🏻