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Wednesday, September 26, 2012

Super-Earths defense of life is weaker than on Earth


Life may exist on the "super-Earths" with a small probability, than on the small-sized planets like the Earth, because they do not have a magnetic field and volcanic centers, necessary for life.

Media writing, based on the statement of the group planetologists Vlada Stamenkovic of the U.S. Massachusetts tehnoinstituta that the purpose of the study - the ability to find out, whether considered "super-Earths" enlarged copies of the earth with the same properties, or they are very fundamentally different from it.


Stamenkovic and his colleagues formed a computer model that can describe the formation of the typical "super-Earths" in the protoplanetary disk volume with Sun Star. The specialists of the model used to calculate the parameters of the lithosphere and atmosphere "super-Earths", and to compare them with similar land shells.

In fact, it became known that the lithosphere of these planets very much different from her "colleagues" on the earth's surface. Firstly, bowels "super-Earths" will consist of a very dense and viscous rock, slowly migrating lithosphere. This means that the tectonic processes associated with volcanoes, and if they have to "super-Earths", it will not be as active as the planets the size of Earth's surface.

It is also important that these planets may not have a pronounced metallic core, the core. So the "super-Earths" may not have a magnetic field, which is needed to protect the atmosphere from the solar wind, living creatures - from cosmic rays and ultraviolet radiation.

In addition, low tectonic and volcanic activity may have a negative impact on the atmosphere and climate of "super-Earths."

An expert of the U.S. News "Market Leader" indicate that volcanic eruptions - the key factor that controls the onset and end of the ice ages.

The work of scientists highlights the importance of understanding the thermal evolution of the planet. Over, the scientists were able to prove that the "super-Earths" quite significantly different from each other, from the other rocky planets. Also, we have the opportunity to get clear answers only when there will be data on the spectrum of the planets in the future observations, - concluded Stamenkovic

Super-Earths, ie sverhzemlya - a class of planets, Earth's gravity is greater than supply, but much less than the weight of gas giants. Term "super-Earths" only helps to describe the planetary mass, but does not depend on the extent of its proximity to its star, no other criteria.

Under the super-Earths means stone of the terrestrial planets, consisting of rock, similar in structure to the ground. Planets of this type in the solar system, the Earth is not present, the largest planet of the Earth in the solar system - is the Earth itself. Another planet - Uranus, which is 14.5 Earth masses, to super-Earths does not apply. Super-Earths is the planet most of the mass of 1.10 Earth masses. Planets of this type have been discovered not so long ago in other star systems. Super-Earths have a small mass, and is difficult to detect Doppler spectroscopy. Open them regularly - the last post was a few days ago

A team of astronomers in Europe led Xavier Bonfil of the Grenoble Observatory Sciences of France opened a "super-Earths  Gliese 163 c, which revolves around a red dwarf star of spectral type M its mass - 6.9 Earth, orbital period right around the world - 25.6 days. According to estimates, Gliese 163 is located from it at such a distance, that is, on the surface it may be water.

Also note that the very Gliese 163, which was investigated by the echelle spectrograph HARPS, is fifty light years from the Earth in the constellation Dorado. Just rotate around three candidate exoplanets: Gliese 163b, which makes the turn around the red dwarf star in 8.6 days, Gliese 163 c and third ekzokandidat - neptunopodobnaya weighing 20 planet earths.

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