Exoplanets & Exomoons

Rotation of Planets Hosting Atmospheric Tides: From Venus to Habitable Super-Earths

By Keith Cowing
Press Release
November 17, 2016
Filed under
Rotation of Planets Hosting Atmospheric Tides: From Venus to Habitable Super-Earths

The competition between the torques induced by solid and thermal tides drives the rotational dynamics of Venus-like planets and super-Earths orbiting in the habitable zone of low-mass stars.

The tidal responses of the atmosphere and telluric core are related to their respective physical properties and strongly depend on the tidal frequency. The resulting torque determines the possible equilibrium states of the planet’s spin. We compute here an analytic expression for the total tidal torque exerted on a Venus-like planet. This expression is used to characterize the equilibrium rotation of the body. Close to the star, the solid tide dominates. Far from it, the thermal tide drives the rotational dynamics of the planet.

The transition regime corresponds to the habitable zone, where prograde and retrograde equilibrium states appear. We demonstrate the strong impact of the atmospheric properties and of the rheology of the solid part on the rotational dynamics of Venus-like planets, highlighting the key role played by dissipative mechanisms in the stability of equilibrium configurations.

Pierre Auclair-Desrotour, Jacques Laskar, Stéphane Mathis, Alexandre Correia
(Submitted on 17 Nov 2016)

Comments: 5 pages, 4 figures, accepted for publication in Astronomy & Astrophysics
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
MSC classes: 85
Cite as: arXiv:1611.05678 [astro-ph.EP] (or arXiv:1611.05678v1 [astro-ph.EP] for this version)
Submission history
From: Pierre Auclair-Desrotour
[v1] Thu, 17 Nov 2016 13:42:08 GMT (1659kb,D)

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