In recent years, astronomers have discovered several thousand planets outside our Solar system.
One of the main issues before scholars can at least some of them to be inhabited.
For the origin of life need a coincidence of several factors, including the presence of the exoplanet’s atmosphere, which protects the surface from cosmic radiation.
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The most common in our galaxy are “red dwarfs”. All the stars in the beginning of its life, emit intense radiation, but over time gradually cool down. If the luminaries, like the Sun, become colder, for a few hundred million years, the “red dwarfs” remain active for billions of years.
Radiation strongly heats the planet’s atmosphere. The gas temperature in the thermosphere of the Earth reaches thousands of degrees Celsius.
Active young stars are able to heat the shell even more, which starts the outflow of gas.
Scientists have calculated that in this case the atmosphere, like the earth, will completely disappear in just a million years – by the standards of evolution, it is almost instantaneous.
They concluded that planets around young “red dwarfs”, with high probability, deprived of the gas envelope and therefore uninhabited. Suitable conditions for life can arise only after reducing the activity lights, which can take billions of years.
As for the Earth, its atmosphere of old, probably saved carbon dioxide – it cooled the upper layers and reflect infrared radiation back into space.
Earlier it was reported that scientists have discovered a second planet in the nearest star to the Sun Proxima Centauri.