According to a new study, there could be more than 30 civilisations capable of long-distance communication here in the Milky Way. Led by researchers at the University of Nottingham, they assumed that intelligent life not only exists off-Earth, but develops on other planets similarly to how it does on Earth. To estimate the number of intelligent civilisations in our galaxy, the team took into account two major ‘Astrobiological Copernican limits’ - conditions that such an ‘intelligent’ civilisation would depend on.
Could there be other life in the Milky Way?
For one of these limiting factors, the researchers used Earth, where life began approximately 4.54 billion years ago, as an example. They assume that intelligent life most likely forms in less than 5 billion years. The second limiting criterion focused on stars. They estimate that a planet with intelligent life would orbit a star like our Sun. This Sun-like star would have “a metal content equal to that of the Sun… the Sun is relatively speaking quite metal-rich,” said Tom Westby, an assistant professor at the University of Nottingham.