Nasa has said that humanity will find direct evidence that we are "not alone" in the universe within 20 years.
The pronouncement comes on the 45th anniversary of the launch of Apollo 11.
Nasa said that it is overwhelmingly likely that life will have emerged somewhere in our galaxy of 100 billion suns, and that we will be able to find evidence that it exists sooner rather than later.
So far our attempts to find life in our solar system have fallen flat. No direct evidence of life has been found on Mars, despite more than a decade of robotic exploration, and while scientists think the moons Titan and Europa could host life under their surface, it's still just conjecture.
But the chances are that life has emerged elsewhere -- and Nasa is still convinced it can find the evidence. We're not talking UFO spacecraft or little green men though, we talking more subtle evidence around distant stars that life has emerged separate to our own planet.
Nasa made its prediction at its Washington HQ, where it also announced the launch of the Transiting Exoplanet Surveying Satellite in 2017 to look for signs of alien life and other worlds outside our star system.
“Just imagine the moment, when we find potential signatures of life. Imagine the moment when the world wakes up and the human race realizes that its long loneliness in time and space may be over — the possibility we’re no longer alone in the universe,” said Matt Mountain, director and Webb telescope scientist at the Space Telescope Science Institute.
"What we didn’t know five years ago is that perhaps 10 to 20 per cent of stars around us have Earth-size planets in the habitable zone. It’s within our grasp to pull off a discovery that will change the world forever."
Nasa predicts that a conservative "100 million" worlds in our galaxy might be able to sustain life.Suggest a correction