Land is an exception among the habitable planets in our galaxy: their chemical composition is totally different from the Earth. This is the conclusion the authors of an article in preprint arXiv. Brief research reports New Scientist. The Portuguese University of Porto and his colleagues studied the stars, the mass and the radius of which is different from the sun, and in the habitable zone of a planet there, where the water is present in liquid form. It was found that iron and other metals in the composition of these stars is less than that of the stars around which address only the uninhabited planet.
Since the planet’s chemical composition close to its star, the celestial bodies in the area of life is usually less metal than in the bowels of the Earth and the Sun, scientists have decided. As a rule, around the iron-rich stars are rotating massive rocky body, wrapped in a giant gasbag. Differences in chemical composition between the Earth and most planets habitable zone can be explained by the fact that the latter is likely to have formed in the distant past of our galaxy. Iron and other heavy elements are formed by the explosion of light and then scattered by interstellar space. When the Milky Way galaxy was young, much less stars end their existence in this way – hence the iron in the ancient extrasolar planets suitable for life, should be less.
If habitable planets are specific to poor metal stars at the present stage of life of the galaxy they formed much less frequently. However, it stresses the light of existing debt, and the ancient planet with favorable conditions for the emergence of organic matter have not gone away – hence the number is only increasing with time.