Interior Dynamics and Outgassing in Tidally-heated Rocky Super-Earths

Abstract:

In the search for a habitable Earth analog it has been recognized that a shortcut is to observe rocky planets around M stars, because their habitable zones are at shorter periods. It is also true that at these distances tidal dissipation raised by the star on the planet becomes critical. Thus, it is important to investigate what are the interior and surface conditions of these tidally heated planets. For low-mass planets, outgassing, which is tied to mantle convection, sets the dominant input component to the atmospheric composition (with atmospheric escape and ingassing the other relevant components), which in turn helps determine the surface temperature and overall habitability profile. We have performed interior dynamic calculations based on [1] tied to a simple outgassing model to investigate the effects of tidal heating in outgassing. I will present results of the effect of planetary mass and tidal heating in outgassing budgets, by taking Earth as the reference state.

[1] Tackley, P. J., M. Ammann, J. P. Brodholt, D. P. Dobson and D. Valencia (2013) Mantle dynamics in super-Earths: Post-perovskite rheology and self-regulation of viscosity, Icarus 225(1), 50-61