Extrasolar Planets

Atmospheric Dynamics Of A Near Tidally Locked Earth-Size Planet

By Keith Cowing
April 24, 2022
Filed under
Atmospheric Dynamics Of A Near Tidally Locked Earth-Size Planet
A Robinson projection of the results from a ROCKE-3D simulation for the exoVenus candidate, Kepler-1649b [50], showing the surface temperature and a Venus topography overlay. The surface temperature reached a maximum of 270◦C and a global mean of 112◦C at the limit of the ROCKE-3D radiation tables.

The discovery and characterization of Earth-sized planets that are in, or near, a tidally-locked state are of crucial importance to understanding terrestrial planet evolution, and for which Venus is a clear analog.

Exoplanetary science lies at the threshold of characterizing hundreds of terrestrial planetary atmospheres, thereby providing a statistical sample far greater than the limited inventory of terrestrial planetary atmospheres within the Solar System. However, the model-based approach for characterizing exoplanet atmospheres relies on Solar System data, resulting in our limited inventory being both foundational and critical atmospheric laboratories.

Present terrestrial exoplanet demographics are heavily biased toward short-period planets, many of which are expected to be tidally locked, and also potentially runaway greenhouse candidates, similar to Venus. Here we describe the rise in the terrestrial exoplanet population and the study of tidal locking on climate simulations. These exoplanet studies are placed within the context of Venus, a local example of an Earth-sized, asynchronous rotator that is near the tidal locking limit.

We describe the recent lessons learned regarding the dynamics of the Venusian atmosphere and how those lessons pertain to the evolution of our sibling planet. We discuss the implications of these lessons for exoplanet atmospheres, and outline the need for a full characterization of the Venusian climate in order to achieve a full and robust interpretation of terrestrial planetary atmospheres.

Stephen R. Kane

Comments: 18 pages, 6 figures, accepted for publication in Nature Astronomy
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2204.09696 [astro-ph.EP] (or arXiv:2204.09696v1 [astro-ph.EP] for this version)
Submission history
From: Stephen Kane
[v1] Wed, 20 Apr 2022 18:00:02 UTC (1,638 KB)

SpaceRef co-founder, Explorers Club Fellow, ex-NASA, Away Teams, Journalist, Space & Astrobiology, Lapsed climber.