Earth-like planets

Nov 22, 2007 16:14 GMT  ·  By

The search for planets outside the solar system ultimately resulted in the discovery of Earth-like planets, or super-Earth and they are generally rocky planets slightly bigger than our planet, so astronomers are speculating what the conditions on those planets might be like. Harvard scientists suggest that Earth-like planets must also have similar plate tectonics, since they have a rocky outer solid surface.

On Earth, the plate tectonics are responsible for seismic events, volcanoes and most of the other geological events, which have dominated our planet's geological past. So far observation regarding the other planets in the our solar system, indicates that Earth is the only recorded planet that presents plate tectonics and this might be one of the necessary conditions for the appearance and evolution of life.

According to planetary scientist Diana Valencia, from Harvard University, planets of masses between one and ten times that of the Earth, present this condition for live to evolve. Part of the super-Earth planets might be at the right distance from their stars, in the so-called habitable zone, which allows water to exist in its liquid state, thus only on these types of planets, with thermal and chemical processes triggered by plate tectonics movement, conditions which are right for life to appear and possibly evolve will be met.

By simulating models of the interior of the planets, the team was able to determine the way the mass of the planet influences the thickness of its plate tectonics and the stress exerted on them. The convection processes which take place below the surface of the planet determine the amount of stress which produce the deformation and subduction of the plates, which would be more active and larger than those observed on Earth.

Even if the planet has no liquid water, they would still exhibit plate tectonic movement. The movement of the plate tectonics increases proportionally with the mass of the planet, thus creating greater stress and decreasing the thickness of the plates. Scientists have shown that the processes of deformation and subduction are easily met especially by larger rocky planets.

Maybe in the near future these results will be directly observed with the help of NASA's Terrestrial Planet Finder devices, or maybe the European Space Agency Darwin project, which plans to launch an array of three telescopes to compose a light interferometer to detect Earth-like planets.