Do X-rays sterilize exoplanets?

Do X-rays sterilize exoplanets?

Artistic vision of an exoplanet orbiting a red dwarf star

A new study by German scientists suggests that intense rays are able to separate the ozone layer of terrestrial-type exoplanets and deprive them of the possibility of life.

We now know about the existence of approximately 4,000 worlds around other stars. Some of them resemble the Earth in size and live in habitats (the temperature is suitable for the presence of liquid water). However, many revolve around cool red dwarfs, where they are forced to be closer in order to get enough heat.

The problem is that such stars release huge amounts of X-rays, which are pulled out in frequent coronal mass ejections. Scientists decided to evaluate this effect on the planets.

In February 2018, we managed to notice a large flash from the AD star Leo, which is 16 light-years distant from us. This star has a giant planet rotating on an orbital path of 3 million km (50 times closer than the Earth-Sun distance). Now researchers are trying to understand exactly how the flash affected the world. Initial analysis shows that the giant was not touched. This is great news for the moment with the advent of life, because emissions of the coronal mass can destroy the atmosphere on smaller planets.

But X-rays are still dangerous. They were supposed to thin the atmosphere and reach the surface in a world resembling the Earth. Then life could be saved only in the ocean.

Scientists plan to continue the study to clarify the details of their model. Some believe that large radiation outbreaks can deplete the ozone layer by 94% in 2 years and can even destroy all life forms.

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