In our home galaxy there could be, according to an estimate under certain assumptions around 36 intelligent civilizations.
Discovery of and communication with these aliens is, with current technology, however, is very difficult, because the average distance between these civilizations amounts to about 17,000 light-years, emphasize Tom Westby and Christopher Conselice of the University of Nottingham. They present their assessment in the journal “The Astrophysical Journal”. A light-year is the distance that the light – and thus, for example, a radio call – back in a year.
The two researchers had asked how many of the communicating terrestrial intelligences (CETI) could give extra, it is in the milky way, probably, could be, in principle, by their radio signals tracking. “The idea is to consider the Evolution on a cosmic scale,” said Conselice. “Under the assumption that it takes how on earth roughly five billion years for intelligent life on other planets is developed, there should be at least a couple of dozen active civilizations in our galaxy.”
For their assessment, the researchers looked at the proportion of sun-like stars in the milky way, with earth-like planets in their habitable temperature zone. In addition, you put as the average lifetime of a communicating civilization in 100 years, as long as there exists the radio communication on the earth. “We calculate that it should be around 36 active civilizations in our galaxy,” says Westby.
“If we find that intelligent life is common, it would indicate that our civilization can clearly exist longer than a few centuries,” said Conselice. “Otherwise, if we find that there is no active civilizations in our galaxy, that is a bad sign for our own sustainable existence.”
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