Stephen Hawking
Physicist Stephen Hawking addresses an audience at the Starmus Festival via video. (Starmus via YouTube)

British physicist Stephen Hawking has repeatedly warned us that we have just a century or two to move off Earth, and he just shared his vision for how to do it.

Hawking laid out a timetable this week during a lecture titled “The Future of Humanity,” presented to an audience of 3,000 attending the Starmus Festival in Trondheim, Norway.

He said a base could be established on the moon within 30 years to serve as a gateway to the rest of the solar system. Settlers could follow up with a Mars base within 50 years. But Hawking went on to call for setting an even speedier schedule for space exploration.

The 75-year-old, wheelchair-riding physicist recalled President John F. Kennedy’s vision of putting Americans on the moon by the end of the 1960s – a deadline that was met with the Apollo 11 mission in 1969.

“A goal of a base on the moon by 2020, and a manned landing on Mars by 2025 would reignite the space program and give it a sense of purpose in the same way that President Kennedy’s target did in the ’60s,” he said, using his computer-generated voice. “The spin-off to this would be an increase in the public recognition of science generally.”

Eventually, humans could take one-way trips to potentially habitable exoplanets as close as Proxima Centauri b.

“This is long-term thinking,” Hawking said. “And by ‘long-term,’ I mean hundreds or thousands of years. It won’t be easy.”

Space settlers would have to carry along “a whole new ecosystem that will survive in an environment we know very little about, and we will of course need to consider transporting several thousands of people, animals, plants, fungi, bacterla and insects,” he said.

Why do it? Hawking and some other deep-thinkers, including SpaceX founder Elon Musk, say it’s only a matter of time before our home planet experiences a potentially civilization-ending crisis – whether it’s nuclear war, catastrophic climate change, a global pandemic or an asteroid strike.

Establishing settlements beyond Earth would serve as an insurance policy, but it would also mark a giant leap in what Hawking regards as a 21st-century brand of manifest destiny. During the Starmus talk, he said the cosmos is “where I believe our ultimate destiny lies.”

Elon Musk and Jeff Bezos, the billionaire founder of Amazon as well as the Blue Origin space venture, are of a similar mind. Musk has said his life’s passion is to turn humanity into a multi-planet species, while Bezos has said his success with Amazon is fueling a personal vision to have millions of people living and working in space.

Last year, Musk laid out his own decades-long plan for sending millions of settlers to Mars, starting in the 2020s. Last week, he said he’s getting ready to update the plan with further details.

But when it comes to thinking long-term, Hawking’s talk in Norway outdid Musk’s talk in Mexico. Although interstellar travel isn’t practical today, Hawking said it should be possible to come up with the required technologies over the next 200 to 500 years.

Among the options could be the beam-driven propulsion system that scientists and engineers are trying to develop for Breakthrough Starshot, a project that’s supported by Hawking as well as deep-pocketed funders such as Russian billionaire Yuri Milner.

Breakthrough Starshot aims to send swarms of mini-probes toward the Alpha Centauri star system, powered by arrays of laser-equipped antennas. The trip is projected to take 20 years, and could include a flyby past Proxima Centauri b.

“If we succeed, we will send a probe to Alpha Centauri within the lifetime of some of you here today,” Hawking told the crowd in Trondheim.

He said other options could include fusion drives or antimatter drives.

Hawking didn’t address how his expansive (and expensive) space vision would be financed. Setting up bases on the moon and Mars is likely to cost hundreds of billions of dollars, and the cost of interstellar flight could well be astronomical.

The physicist did give a nod to commercial space efforts during his talk, noting that he’s still looking forward to taking a suborbital ride into space aboard Virgin Galactic’s SpaceShipTwo rocket plane.

“I believe it is up to scientists like me, together with innovative commercial entrepreneurs, to do all we can to promote the excitement and wonder of space travel,” he said.

President Donald Trump has also said he wants to see a speed-up in the pace of space exploration. “American footprints on distant planets are not too big a dream,” Trump told a joint session of Congress in February.

However, Hawking has sharply criticized Trump for his stance on climate change. At one point he noted that it takes 4.3 years for radio transmissions to reach the Alpha Centauri system, and joked that “if there are beings alive on Alpha Centauri today, they remain blissfully ignorant of the rise of Donald Trump.”

At another point, Hawking referred to Trump in his reply to the anticipated criticism that we should be focusing our resources on saving our own planet rather than looking for a different home in the cosmos.

“I am not denying the importance of fighting climate change and global warming, unlike Donald Trump, who may just have taken the most serious and wrong decision on climate change this world has seen,” Hawking said. “I am arguing for the future of humanity, and the long-term strategy to achieve this.”

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