An estimated 30 intelligent civilisations are in our galaxy
There are over a billion stars in our own galaxy, the Milky Way, and most of the people on the Earth believe that there is some form of intelligent civilisation existing on other planets.
Obtaining good estimates of the number of possible extraterrestrial civilisations has, however, been very challenging. Are we the only living life form in the galaxy?
A new study by University of Nottingham, published in The Astrophysical Journal, has taken a new approach to this problem. Using the assumption that intelligent life forms on other planets in a similar way as it does on Earth, researchers have obtained an estimate for the number of intelligent communicating civilisations within the Milky Way. They calculate that there could be over 30 active communicating intelligent civilisations in our home galaxy.
Professor of Astrophysics at the University of Nottingham Christopher Conselice, who led the research, explains, "There should be at least a few dozen active civilisations in our galaxy under the assumption that it takes 5 billion years for intelligent life to form on other planets, as on Earth." Conselice also explains that, "The idea is looking at evolution, but on a cosmic scale. We call this calculation the Astrobiological Copernican Limit."
