Astronomers from the Department of Astronomy at Beijing Normal University Wenjie Song and He Gao have published a new study in which they tried to find out how long humanity will have to wait to get an answer from aliens, Universe Today reports.
To answer the question, the authors of the study tried to count how many communicating extraterrestrial intelligent civilizations (CETIs) exist in the Milky Way. The astronomers' work was published in The Astrophysical Journal.
To determine the number of extraterrestrial civilizations in the Milky Way that humanity has a chance to make contact with, astrophysicists used the Drake Equation with different values of the variables.
In the first optimistic scenario, alien civilizations originated and evolved when the stars near their planets were young enough. In that case, there may be 42 thousand CETIs in our galaxy, and we may encounter one of such civilizations in two thousand years.
In the second pessimistic scenario, civilizations arise near parent stars that have lived at least 75% of their lives. Then there may be only 111 CETIs in the Milky Way. In this case, it would only be possible to establish two-way communication with aliens in 400,000 years.