New study puts extraterrestrial life in big question

New study puts extraterrestrial life in big question
New study puts extraterrestrial life in big question
Anonim

Scientists have concluded that life on planets near red dwarfs - the most common stellar objects in the universe - probably cannot arise. If the conclusions are correct, then this, on the one hand, will greatly complicate the search for extraterrestrial life forms, and on the other, it will narrow the range of search.

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Researchers consider red dwarfs to be the most abundant stars in the universe. It is among such objects that Proxima Centauri belongs, which is the closest star to the Sun. Orbiting next to it is the planet Proxima Centauri b, which some experts say is potentially habitable. In addition, twenty of the thirty closest stars located further away from Proxima Centauri are also referred to as red dwarfs.

It is not surprising that such luminaries are of particular interest to scientists. In the scientific community, there is a fierce debate about the suitability of planets located near such stars. The new findings of experts representing Harvard University and the Harvard-Smithsonian Center for Astrophysics do not speak in favor of their viability. The scientists presented their findings in The Astrophysical Journal, and a brief overview can be found in ScienceAlert.

The researchers tried to assess whether stellar objects are capable of producing the amount of UV radiation needed to form life. This is considered a prerequisite for the appearance of RNA (ribonucleic acid), which transfers genetic information from DNA to protein-synthesizing ribosomes and performs a number of other important functions. There is a hypothesis according to which it was RNA that preceded cells, having the ability to copy itself and being the world's first enzymes.

The model built by American scientists showed that the planets located next to red dwarfs have 100-1000 times less access to UV radiation than the young Earth. In other words, the chemical processes necessary for the origin of life and taking place on our planet are very unlikely on the exoplanets closest to our system. According to an alternative version, such chemical processes can still take place, but their speed will still be incomparably lower than that which was observed on Earth billions of years ago.

Study authors are slow to draw far-reaching conclusions. Moreover, an excess of UV radiation is just as destructive to life. “There has to be enough ultraviolet radiation to cause life to form, but not enough to destroy the planet’s atmosphere,” says study co-author Robin Wordsworth. New research will help to confirm or disprove the findings.

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