An estimate for when first contact with an extraterrestrial civilization would occur

Is our Milky Way home to advanced extraterrestrial civilizations that could communicate with humanity? The question still has not found a definitive answer. This does not prevent researchers from speculating. And to imagine how long we will have to wait to get in touch.

For a little over 60 years now, humanity has been straining its ears towards space,listening to aliens. Since two physicists renowned have postulated that if technologically advanced extraterrestrial civilizations exist somewhere in the Milky Way, they probably communicate with each other. But more than 60 years have passed and still nothing. Nothing surprising in this, we are now noticing Beijing Normal University researchers (China). According to their calculations, we may have to wait some 400,000 years for the chance to pick up another civilization’s message!

The kind of civilization that could give us a sign is what scientists call the communicating extraterrestrial civilizations, the Ceti — for Communicating extraterrestrial intelligent civilizations. In 2020, researchers at the University of Nottingham (United Kingdom) felt that there might be, in our Milky Way, at least 36 of these civilizations ready to enter into dialogue with us. And possibly as many as 2,900 of these advanced extraterrestrial populations.

Even if all this remains extremely uncertain, researchers at Beijing Normal University (China) are also trying to come up with a model based on logical assumptions. To produce, above all, a plausible estimate of the rate of occurrence of Ceti. By focusing on two parameters that are as little known as each other. First the number of habitable Earth-like planets and the frequency at which life on these planets evolves into a Ceti. Then the stage of the evolution of a host star at which a Ceti could appear.

2,000 years, 400,000 years or… never!

The researchers named f_vs the probability of seeing a Ceti appear on an exoplanet. And F, the stage of evolution of the required host star. By injecting different values ​​of these variables into their simulations, they arrive at two scenarios. One rather optimistic. The other much more pessimistic.

So in the best case, a star must have lived 25% of its life before a Ceti emerges and for each habitable planet around it, the chance of this happening would be 0.1%. As a result, no less than 42,000 Ceti populate – or would have populated, since they may as well have already disappeared – the Milky Way. Humanity would then only need to wait 2,000 years to hope to establish communication. Sounds within reach, right?

Unfortunately, this remains the most pessimistic scenario proposed by the researchers. With an F=75% and an fc=0.001%. Then the Milky Way would have seen the birth of only 111 Ceti. And we shouldn’t expect to come into contact with any of them for 400,000 years! Always within reach, do you think? Researchers are more reserved. Because many pitfalls can limit the lifespan of a civilization. A global warming or a nuclear disaster, for example. Or why not, the explosion of a supernova or thedevastating impact of an asteroid. The Argument doomsday — understand, the doomsday argument — as scholars call it. So maybe we will never get the answer to the big question. But the dream, it remains more than ever allowed!