Scientists say it’s ridiculously unlikely that we are universe’s first intelligent culture.
A calculation gives odds of less than one in 10 billion trillion that aliens haven’t developed technology like ours.
Which means that – either now or in the past – numerous advanced civilisations must have existed on worlds besides our own.
Professor Adam Frank from the University of Rochester, who co-authored the new paper, said our experience on earth was far from unique.
“One in 10 billion trillion is incredibly small,” he said. “To me, this implies that other intelligent, technology producing species very likely have evolved before us.
“Before our result you’d be considered a pessimist if you imagined the probability of evolving a civilisation on a habitable planet were one in a trillion.
“Now even that guess implies that what’s happened here on Earth with humanity has in fact happened about a 10billion other times over cosmic history.”
The odds were arrived at by adjusting the Drake equation from the 1960s, which calculates the likelihood that alien civilisations exist.
It’s a sum that examines the number of habitable planets in the universe and then the likelihood of civilisation arising on them.
But the new equation removes one of the big unknowns from its predecessor, how long advanced cultures will likely exist.
It also dispatches with the question of how probable it is for civilisation to arise on habitable planets.