Is There Evidence That Ancient Aliens Existed But Are Now Extinct?

New research shows that other technologically advanced civilizations apart from our planet may have existed in our universe, but they are most likely extinct or were young to have had communication with us.

Many scientists are still reluctant to acknowledge extraterrestrial life, but researchers from the University from Rochester reveals that the probability of highly-advanced aliens is still high.

Using a simplified from of Frank Drake's Drake Equation, researchers tried to calculate the odds of the existence of life in the universe by incorporating the observations of exoplanets with habitable zones made by NASA's Kepler satellite and other planetary searches.

According to the study, published in the journal Astrobiology, human civilization is likely to be unique in the universe only if the odds of a civilization developing on a habitable planet are less than about one in 10 billion trillion, or one part in 10²².

"One in 10 billion trillion is incredibly small," said Adam Frank, professor of physics and astronomy at the University of Rochester and co-author of the paper, said in a statement.

 "To me, this implies that other intelligent, technology producing species very likely have evolved before us. Think of it this way. Before our result you'd be considered a pessimist if you imagined the probability of evolving a civilization on a habitable planet were, say, one in a trillion. But even that guess, one chance in a trillion, implies that what has happened here on Earth with humanity has in fact happened about a 10 billion other times over cosmic history!" Frank added.

On the other hand, the odds of another technological planet to exist our galaxy, the Milky Way, are better than one chance in 60 billion.

"The universe is more than 13 billion years old," noted Woodruff Sullivan of the astronomy department and astrobiology program at the University of Washington and co-author of the study.

 "That means that even if there have been a thousand civilizations in our own galaxy, if they live only as long as we have been around-roughly ten thousand years-then all of them are likely already extinct. And others won't evolve until we are long gone. For us to have much chance of success in finding another "contemporary" active technological civilization, on average they must last much longer than our present lifetime." Sullivan explained.

According to the authors, their study is not simple to determine if life beyond earth is still probable, but also to help other researchers better understand the sustainability and climate change crisis we are currently experiencing.

 "Our results imply that our evolution has not been unique and has probably happened many times before. The other cases are likely to include many energy intensive civilizations dealing with their feedbacks onto their planets as their civilizations grow. That means we can begin exploring the problem using simulations to get a sense of what leads to long lived civilizations and what doesn't," the authors concluded.