Massive exoplanets may be more Earth-like than previously believed

A team of researchers have said that massive exoplanets, called "Super-Earths," are much likelier to have an Earth-like climate than previously believed.

Nicolas B. Cowan, a postdoctoral fellow at Northwestern's Center for Interdisciplinary Exploration and Research in Astrophysics, and Dorian Abbot, an assistant professor in geophysical sciences at University of Chicago, new model conclude that most tectonically active super-Earths -- regardless of mass -- store most of their water in the mantle and will have both oceans and exposed continents, enabling a stable climate like Earth's.

In their model, Cowan and Abbot treated the intriguing exoplanets like Earth, which has quite a bit of water in its mantle, the rocky part that makes up most of the volume and mass of the planet.

The rock of the mantle contains tiny amounts of water, which quickly adds up because the mantle is so large. And a deep water cycle moves water between oceans and the mantle.

Water is constantly traded back and forth between the ocean and the rocky mantle because of plate tectonics, Cowan and Abbot say. The division of water between ocean and mantle is controlled by seafloor pressure, which is proportional to gravity.ccounting for the effects of seafloor pressure and high gravity are two novel factors in their model. As the size of the super-Earths increase, gravity and seafloor pressure also go up.

The study has been published in the Astrophysical Journal.