Researchers from the University of Nottingham (Great Britain) have suggested that extraterrestrial life in the Milky Way at the moment can be represented by dozens of developed civilizations. It is reported by The Astrophysical Journal.
British astrophysicists took the hypothesis according to which intelligent life on other planets of our galaxy could form in the same time and under similar conditions as on Earth.
Researchers' calculation method is based on the assumption that the possibility of the development of extraterrestrial civilizations in our galaxy is determined by basic parameters. Scientists called them the astrobiological limits of Copernicus. The main such parameter (the first limit) is the age of the planets on which a civilization similar to Earth could form - about 5 billion years.
An additional parameter (the second astrobiological limit), scientists called the high metallicity of the stars in the orbit of which the planets are located - a large concentration of heavy elements (heavier than hydrogen and helium) . After analyzing the known data about our galaxy and applying both parameters to them, scientists received a hypothetical number of Milky Way civilizations.
“According to our data on the two astrobiological limits of Copernicus, intelligent life forms have been developing for about 5 billion years - like an earthly scenario. Having set tough parameters, in particular, a high metal content equal to the solar one (the Sun has relatively many metals), we calculated that there should be about 36 active civilizations in our galaxy, ”explains Tom Westby, one of the authors of the study.
According to the calculations of astrophysicists, the average distance to possible civilizations is 17 thousand light years. This makes it difficult to detect reasonable "neighbors" and establish contact with them. At the same time, scientists do not exclude that earthlings are currently the only intelligent inhabitants of the Milky Way, since the life time of civilizations like ours can be very short.
Also, according to astrophysicists, a further search for the existence of extraterrestrial intelligence will lead to an understanding of how long our civilization can exist.