The long-standing question of whether extraterrestrial life exists across the Universe or not seems to have received another boost as new research calculated there could be over 30 intelligent civilizations in our galaxy alone. This is a rather massive advance over earlier estimates, which stretched from zero to billions.
One of the long-existing questions in the history of human thought is whether there are other intelligent life forms within our Universe, but gathering good estimates of the number of feasible extraterrestrial civilizations have been incredibly challenging so far.
More Than 30 Civilizations in Our Galaxy
New research conducted by scientists at the University of Nottingham and published today in The Astrophysical Journal has found a new method to tackle this problem. Using the presumption that intelligent life forms on other planets in a comparable way as it does on Earth, scientists have managed to get an estimate for the number of intelligent communicating cultures within the Milky Way: they suggested there could be more than 30 active communicating intelligent civilizations in our 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 civilizations in our galaxy under the assumption that it takes 5 billion years for intelligent life to form on other planets, as on Earth. The idea is looking at evolution but on a cosmic scale. We call this calculation the Astrobiological Copernican Limit.”
First author Tom Westby also added to Professor Conselice’s explanation: “The classic method for estimating the number of intelligent civilizations relies on making guesses of values relating to life, whereby opinions about such matters vary quite substantially. Our new study simplifies these assumptions using new data, giving us a solid estimate of the number of civilizations in our galaxy.”
“The two Astrobiological Copernican limits are that intelligent life forms in less than 5 billion years, or after about 5 billion years—similar to on Earth where a communicating civilization formed after 4.5 billion years. In the strong criteria, whereby a metal content equal to that of the Sun is needed (the Sun is relatively speaking quite metal-rich), we calculate that there should be around 36 active civilizations in our galaxy,” Westby said.
If Intelligent Life is Common
The result of the study shows that the number of civilizations relies strongly on how long they are actively transmitting signals of their existence into space, such as radio transmissions from satellites, television, and so on. If other technological groups last as long as ours, namely 100 years old, then there will be approximately 36 ongoing intelligent technical civilizations across our galaxy.
Still, the standard distance to these cultures would be 17,000 light-years away, which makes detection and communication incredibly difficult with our current technology.
Professor Conselice explains further: “Our new research suggests that searches for extraterrestrial intelligent civilizations not only reveals the existence of how life forms, but also gives us clues for how long our own civilization will last. If we find that intelligent life is common, then this would reveal that our civilization could exist for much longer than a few hundred years, alternatively, if we find that there are no active civilizations in our galaxy, it is a bad sign for our own long-term existence. By searching for extraterrestrial intelligent life—even if we find nothing—we are discovering our own future and fate.”