Receiving signals from ET requires a lot of patience: in the most optimistic forecasts, man would have to survive at least 300,000 years to see one, while in the most pessimistic ones much more, about 50 million years.
This is the prediction made by a study from the Normal University of Peking and published in The Astrophysical Journal, which tried to estimate the two fundamental factors: the probability that life appears on terrestrial-type planets, evolving into an intelligent civilization capable of communicate, and at what moment in the life of the host star this civilization could be born.
To ensure the completeness of the simulation, study authors Wenjie Song and He Gao considered different combinations for the two fundamental variables.
The more optimistic situation, which sees a probability of intelligent life on other planets equal to 0.1% and an evolution of this civilization already during the first part of the life of the host star, indicates that about 42,777 life forms could be born capable of communicate with us.
The duration of these civilizations should be at least 3 years to be able to achieve one-way communication and at least 2,000 years for a two-way one.
In this case, humans must survive for at least 300,000 years to receive the message.
At the opposite end of the spectrum of simulations is the most pessimistic one, with a probability of the evolution of intelligent life forms of 0.001%, in the final phase of life of the star around which the planet rotates.
With these starting data, the number of possible extraterrestrial civilizations is reduced to about 111, which should survive for at least 800,000 years for one-way communication and 900,000 for two-way communication.
This means that man's existence would have to extend for 50 million years before he could speak to ET.
