Washington, April 22 : Eminent scientist Stephen Hawking has called for a massive investment in establishing colonies on the Moon and Mars, arguing that the world should devote about 10 times as much as 0.25% of its financial resources to space.
According to a report in New Scientist, Hawking expressed his views at George Washington University in Washington, DC, US, on the occasion of NASA's 50th anniversary.
In his speech, Hawking focused on near-term possibilities, backing NASA's goals of returning astronauts to the Moon by 2020 and sending humans to Mars soon after that.
"The Moon is a good place to start because it is close by and relatively easy to reach," said Hawking. "The Moon could be a base for travel to the rest of the solar system," he added.
Mars would be the obvious next target, with its abundant supplies of frozen water, and the tantalising possibility that life may have been present there in the past, according to Hawking.
Some space experts have recently called for NASA to send astronauts to a near-Earth asteroid instead of the Moon as a next step.
Hawking did not mention the idea, but said that any long-term site for a human base should have a significant gravity field. That's because long missions in microgravity lead to health issues such as bone loss.
He also called for an acceleration of NASA's plans for human landings on Mars, which one NASA study suggested could be done in the early 2030s.
"A goal of a base on the Moon by 2020 and of a manned landing on Mars by 2025 would reignite the space programme and give it a sense of purpose in the same way that President Kennedy's Moon target did in the 1960s," he said.
Eventually, according to Hawking, humanity should try to expand to Earth-like planets around other stars.
"No such planets are known so far. But even if only 1% of the 1000 or so stars within 30 light years of Earth has an Earth-size planet at the right distance from its star for liquid water to exist, that would make for 10 such planets in our solar system's neighbourhood," he said.
"We cannot envision visiting them with current technology, but we should make interstellar travel a long-term aim. By long term, I mean over the next 200 to 500 years," he added.