The calculations were based on the Drake equation, created by astronomer and astrophysicist Frank Drake in 1961 and the study is signed by Tom Westby and Christopher J. Conselice, researchers at the University of Nottingham, in the United Kingdom.
“Drake has developed an equation that, in principle, can be used to calculate how many intelligent extraterrestrial communication (CETI) civilizations may exist in the galaxy,” the study authors wrote.
Starting from the Drake equation, they developed what they call the Copernican Astrobiological Principle, which establishes parameters for the existence of life in the galaxy. These equations include several factors, such as the probability of stars hosting Earth-like planets in their habitable zones; where there are conditions for life to develop.
Using the assumption that intelligent life forms on other planets are similar to those on Earth, researchers estimated the number of intelligent civilizations in the Milky Way.
“There should be at least a few dozen active civilizations in our galaxy, under the assumption that it takes 5 billion years for intelligent life to form on other planets, like on Earth,” Conselice said.
The research says that to estimate the number of civilizations it is necessary to take into account how long they have been sending signals of their existence into space, such as radio transmissions from satellites or television. If other technological civilizations are as old as ours, which started emitting these signals about 100 years ago, scientists have calculated that there could be at least another 36 intelligent civilizations currently active in our galaxy.
However, these civilizations would be at an average distance of 17 thousand light years from Earth, which would make their detection difficult with currently available technology.
“Our new research suggests that the search for intelligent extraterrestrial civilizations not only reveals the existence of how life forms, but also gives us clues as to how long our civilization will last. By searching for extraterrestrial intelligent life, even if we don’t find anything, we are learning about our own future and discovering what our destiny will be,” Conselice said.
