Physicist Stephen Hawking, Facebook founder Mark Zuckerberg and Russian internet billionaire Yuri Milner have announced a project that could send microscopic spaceships to hunt for extraterrestrial life in the far reaches of space.
The $100m project, known as Breakthrough Starshot, will examine the possibility of sending a host of tiny spacecraft far beyond the boundaries of our solar system to our nearest neighbour, the Alpha Centauri star system.
The project aims to find out whether the "nanocraft", each weighing far less than an ounce, could fly at a fifth of the speed of light and capture images of possible planets and other scientific data.
Current spacecraft would take around 30,000 years to get to Alpha Centauri, which is 25 trillion miles or 4.37 light years away.
But the nanocraft, powered by a sail pushed by a light beam, could potentially travel the distance over 1,000 times faster and make the journey in 20 years.
The project is the latest part of Mr Milner's years-long search for extraterrestrial life.
Speaking at the One World Observatory in New York, Prof. Hawking, who is on the board of the Breakthrough Starshot initiative, said: "What makes human beings unique, there are many theories.
"Some say it's language or tools, others say it's logical reasoning. They obviously haven't met many humans. I believe what makes us unique is transcending our limits.
"Gravity pins us to the ground but I just flew to America. I lost my voice but I can still speak thanks to my voice synthesiser. How do we transcend these limits? With our minds and our machines.
"The limit that confronts us now is the great void between us and the stars, but now we can transcend it.
"With light beams, light sails and the lightest spacecraft ever built we can launch a mission to Alpha Centauri within a generation.
"Today we commit to this next great leap into the cosmos because we are human and our nature is to fly."
Astronomers estimate there is a reasonable chance of an Earth-like planet existing in the "habitable zones" of Alpha Centauri's three-star system.
A number of scientific instruments, based on Earth and in space, are being developed and will soon identify and characterise planets around nearby stars.