Super-Earths give theorists a super headache

Melting in super-earths.

We examine the possible extent of melting in rock-iron super-earths, focusing on those in the habitable zone. We consider the energetics of accretion and core formation, the timescale of cooling and its dependence on viscosity and partial melting, thermal regulation via the temperature dependence of viscosity, and the melting curves of rock and iron components at the ultra-high pressures charac...

Geological consequences of super-sized Earths

[1] The discovery of terrestrial-scale extrasolar planets, and their calculated abundance in the galaxy, has prompted speculation on their surface conditions and thermal structure. Both are dependent on the tectonic regime of a planet, which is itself a function of the balance between driving forces, and the resistive strength of the lithosphere. Here we use mantle convection simulations to sho...

Inevitability of Plate Tectonics on Super-earths

The recent discovery of super-Earths (masses ≤ ) has initiated a discussion about conditions for habitable 10 M worlds. Among these is the mode of convection, which influences a planet’s thermal evolution and surface conditions. On Earth, plate tectonics has been proposed as a necessary condition for life. Here we show that super-Earths will also have plate tectonics. We demonstrate that as pla...

Collisional Stripping and Disruption of Super-earths

The final stage of planet formation is dominated by collisions between planetary embryos. The dynamics of this stage determine the orbital configuration and the mass and composition of planets in the system. In the solar system, late giant impacts have been proposed for Mercury, Earth, Mars, and Pluto. In the case of Mercury, this giant impact may have significantly altered the bulk composition...

Convection scaling and subduction on Earth and super-Earths