LONDON — The search for extraterrestrial life received a major boost Monday with the launch of an ambitious $100 million program, backed by famed physicist Stephen Hawking and tech billionaire Yuri Milner.

Combining unprecedented computing capacity with the world’s most powerful telescopes, Hawking and the Russian-born Milner seek to intensify the so-far fruitless search for life beyond the planet Earth.

It is a coordinated plan to use the latest scientific methods to solve one of mankind’s enduring riddles: Are we alone?

Hawking, who speaks using a computer-generated voice due to the effects of motor neuron disease, explained the reason for the project: “We are alive. We are intelligent. We must know.”

Milner, who made a fortune through investments in companies like Facebook, said the power of Silicon Valley technology and innovation would be used.

“The scope of our search will be unprecedented: a million nearby stars, the galactic center, the entire plane of the Milky Way and 100 nearby galaxies,” Milner told a packed news conference at the Royal Society in London.

Organizers say the “Breakthrough Initiatives” project, also endorsed by other prominent British scientists, is the biggest ever scientific search for alien life. It includes a “listening” program – the effort to analyze vast amounts of radio signals in search for signs of life – and a “messaging” program that will include $1 million in prizes for digital messages that best represent the planet Earth.

The messages will not be sent, however, in part because some scientists – including Hawking – fear messages sent into space could possibly spur aggressive actions by alien races.

It will be supported by the 100-meter Robert C. Byrd Green Bank Telescope in West Virginia and the 64-meter Parkes Telescope in New South Wales, Australia.