Alien life was once plentiful across the universe but we will never make contact with any because they've all died out - a new theory suggests.
Scientists believe that space may have been populated by a vast number of alien communities in the past after analysis showed that as many as one fifth of all stars are orbited by planets that could sustain life.
The scientists behind this theory are Adam Frank and Woodruff Sullivan, who work at the astronomy department and astrobiology program at the University of Washington.
Startlingly, they argue that there is a minute probability of just one in 10 billion trillion that there has never been any extra-terrestrial life in space.
They still are out there. The cognitive dissonance is breathtaking. To read more, click here.