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Almost all "of the planet-oceans" must be habitable, astronomers say
Material posted: Gornova Anna M.Publication date: 04-09-2018
Most of the "planet-oceans", composed almost entirely of water, should remain habitable for a very long time, about a billion years, what was previously impossible. To such conclusion scientists, who published an article in the Astrophysical Journal.

"Our calculations show that it is not necessary to have a complete "clone" of the Earth, with her oceans and continents, for the origin of life. On average, about 10% of the worlds oceans will have the correct position in orbit and composition to ensure that their climate has remained stable for several billion years," said Edwin Kite (Edwin Kite) at the University of Chicago (USA).

Infinite water

Over the past few years the orbital telescope Kepler, CoRoT, and their terrestrial counterparts has opened more than a thousand exoplanets, and several thousand possible candidates for this role. Most of them refers to the number of hot Jupiters, however, the new methods allow you to find more small planets. A growing number of potential counterparts of Land are increasingly forcing scientists to think about what some of them can support life.

Many of rocky planets are so-called "supertall" – their mass, size and density are approximately in the middle between the earth and the gas giants. For this reason, planetary scientists today do not believe that these worlds are similar in their appearance on our planet – it is possible that they represent an "ocean" of the planet, most of the mass of which is water.

Most scientists, according to the Kite today believes that such water-worlds will almost always uninhabited and uninhabitable. Her birth would interfere with a whole galaxy of factors.

For example, the emergence of the first microbes will interfere with the total lack of "bricks of life" and critical trace elements, and in the future life must disappear due to the fact that such a planet will be "eternal" greenhouse climate. In addition, the lack of circulation of substances between the lithosphere, hydrosphere and atmosphere will make the climate and ecosystems of such planets are extremely unstable and unsuitable for life.

Kite and his colleague Eric Ford (Eric Ford) from the University of Pennsylvania (USA) tested whether this is actually creating a computer model of the water world whose properties can be varied in a very wide range of values. For example, scientists could change a lot of water, the acidity of the ocean, the amount of carbon dioxide in water and air and many other factors that affect the climate of the planet.

Brothers in mind

As shown by these calculations, the concerns of planetary scientists have been somewhat exaggerated. Most oceanic planets, if they are within the "zone of life" of a star similar to the Sun, will remain potentially habitable for several hundred million years, which should be enough for the emergence and existence of life.

More "lucky" planet, whose oceans have considerable depth and contain a lot of carbonates, salts of carbonic acid, and the atmosphere consists of nitrogen, will remain habitable indefinitely, as the CO2 concentration they almost will not change.

In total, approximately one in every four world-ocean should remain habitable for at least a billion years, and every tenth planet of this type will be suitable for existence of life in the surface waters for longer time.

All this, according to Kite, suggests that the number of potentially habitable aksamitov now greatly undervalued, and that "brothers in mind" must be sought not in all twins of the Earth, on oceanic planets, whose number is several orders of magnitude higher.


Tags: strategy , space , water

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