Maybe we shouldn’t be here. In fact, life as we know it is much more likely to develop in the distant future than it did on Earth, around 4 billion years ago, just 600 million years after our planet formed. . That, at least, is what a team of researchers coordinated by physicist Avi Loeb, from the Harvard-Smithsonian Center for Astrophysics, maintains in their latest work, which will be published in the Journal of Cosmology and Astroparticle Physics .
Some scientists believe that between the birth of the universe, about 13.8 billion years ago, and the appearance of the first living things on Earth, it takes long enough for life to have flourished on other worlds older than ours. The conditions were already there only 30 million years after the big bang, when the first stars fed the cosmos with the elements necessary for such a possibility, such as carbon and oxygen. When 10 billion years have passed, the last stars will disappear and the universe will no longer be habitable .
The time these objects last is, in this sense, a key factor for the development of life. The more massive a star is, the shorter its existence tends to be. Thus, those that have more than three times the mass of the Sun could be extinguished before any organism develops in its system. On the contrary, the less massive ones persist for much longer, and the probability that life forms will emerge around them increases. So Loeb and his team calculate that it is a thousand times easier for this to happen in the distant future than it is today .
“We could ask ourselves why we are not living many years from now in a system presided over by a not very massive star,” says this researcher. “One possibility is that we are simply premature; another, that the environment near these types of objects, such as red dwarfs, is not favorable for the emergence of life forms,” he says.
And is that the aforementioned red dwarfs, for example, can be very harmful. In their early stages of development, they are known to emit extremely intense solar flares and enough ultraviolet radiation to sterilize a planet in the habitable zone. To determine if this is the case or if life on Earth has emerged too early, Loeb proposes to thoroughly study nearby systems dominated by red dwarfs, a task that will be facilitated by future space observatories James Webb and TESS.
Image: ESO / L. Calçada
