The celebrated cosmologist teams up with billionaire Russian entrepreneur Yuri Milner as they launch a quest to discover life elsewhere in the universe.
Mr Milner, who is based in California and Moscow, wants to harness the innovation of Silicon Valley to scan the skies for signs of life, including searching the entire Milky Way and 100 nearby galaxies.
His Breakthrough Initiatives project will provide $100m over the next 10 years to bodies searching for extra-terrestrial intelligence.
Some of the world’s largest radio telescopes will be used to scan for distinctive radio signals that could indicate the existence of intelligent life. Astronomers will listen to signals from the million star systems nearest to earth and the 100 closest galaxies, although they do not yet plan to send messages back into space.
The public will also be invited to enter a $1m competition to compose the best message to send into space.
Read more: how close are we to discovering alien life?
Launching the venture at London’s Royal Society on Monday, Mr Milner – who has made his fortune through investments in technology companies such as Facebook – stated that the “public conversation” about life elsewhere in the universe has not significantly changed since in the past 90 years.
In 1924 the US government declared “National Radio Silence Day”, which asked radio users to stop broadcasting for five minutes every hour, with the prediction that Mars could use radio waves to communicate with planet earth.
“Over the last half-century astronomers have significantly refined their research technology,” Mr Milner said. “But they often operated on a shoestring budget from government funds and Silicon Valley donors, and they often relied on the passion of enthusiasts.”
Read more: Is there anybody out there? New planet could hold life
Professor Hawking – whose best-selling book A Brief History of Time covers a range of subjects including big bang and black holes – joined Mr Milner at today’s launch, telling reporters: “We believe that life arose spontaneously on earth, so in an infinite universe there must be other occurrences of life.”
He noted that if Breakthrough Initiatives found no evidence of extra-terrestrial life, “it will not prove that we are alone – but it will narrow the possibilities, and it’s likely to produce data that is fascinating in its own right”.
Astronomer Geoff Marcy, who is also involved in the project, likened it to listening to a cosmic piano with 10 billion keys – but with the capacity to identify any one note that stands out against the background noise.
“Our electronics will be designed to pick out any note with a frequency that is ringing consistently true against the background noise of the 10 billion notes out there,” he said.