Researchers from the University of Pennsylvania (USA) stated the need for revision of inhabitation zone as concepts and suggested that, based on more accurate, in their opinion, the accounting for the effects of greenhouse gases on planetary temperature.

According to the new model (and contrary to previous), Kepler-22b and Gliz-SS lie outside the area of inhabitation (highlighted in green). Yes, and the Earth is critically close to the same. (Here and below illustrate Chester Herman.)

Scientists were based on models James Casting and Evan PU. But the results were the original, its: zone habitability is actually farther from the star than was considered; its near to the sun border, therefore, is also deleted. Calculations for Solar system, for example, has brought amazing results: it turns out that the Earth is barely suitable for living and livable planet could extend to the orbit of Mars.

How so? Lead author Ravi Kumar to Kopparapu (Ravi Kumar Kopparapu) reported that his group had used the last time the database on the absorption of solar radiation, greenhouse gases (HITRAN and HITEMP). In parameters for water and carbon dioxide refined and superior to the previously available values. Using the same model Casting, which is the basis of modern mainstream-assessments, researchers inevitably would get a different value of the habitable zone for exoplanets. Which is what happened.

The result is obvious: many considered habitable planets in practice is far from places where there could be life.

We can already foresee puzzled questions astronomical community. First, early computing, and high values of the absorption of water and carbon dioxide, the Earth was at the edge of the habitable zone inside. Even then, these calculations has caused some distrust: it turned out that, whether our planet just 0.9A. that is from the Sun, its habitability would be woefully low, more precisely - there would be. In the new model, the gap is even less. Look, for example, calculator habitable zone, laid authors online. Now, minus the fraction of a percent of the distance to the Sun, and the Earth would be a dead?

Secondly (and this is even more important reason for criticism), the amount of carbon dioxide on the Earth just three to four hundred million years ago, it was several times higher than today. Yes, the luminosity of the Sun was less - but just on the interest that can be counted on the fingers of one hand. Finally, 40 million years ago, the ice sheet in Antarctica (located roughly in the same place where now) did not exist. However, only 30 million years ago, the ice-covered continent and led him into a modern look - and all because of the fall in carbon dioxide in the atmosphere. It turns out that before the glaciation of Antarctica (and earlier, during the Carboniferous period), according to new calculations, the planet was at least partially be located outside the area of inhabitation?



Note that the calculator atmospheric pressure on the surface of the planet (influencing the greenhouse effect), as its size and the resulting geothermal heat (very large "supertall"), does not affect the habitability, it is not very clear. Again already in solar luminosity in 1,015 from today (so it will be over 200 million years) calculator finds the loss of Ground water shell. Is our life so vulnerable?

Furthermore, the model does not include the effect of clouds, scattering into space solar radiation increase the Earth's albedo. If at the moment we thoroughly unknown feedback mechanisms between rising temperatures and cloud formation, how can you talk about understanding the internal borders of the zone of habitability? If you believe a series of recent research, it turns out that the products of life activity of plants and many germs can play in the formation of clouds same role, as well as all other factors combined. If so, how can you define the exact borders of the zone of habitability without exhaustive information about microbes and plants for many light years from us?

Report on the study accepted for publication in the Astrophysical Journal, and its Preprint available here.

Based on the materials of the University of Pennsylvania.