Stephen Hawking has called for a new diaspora, telling a Hong Kong press conference that humanity must leave Earth and colonise the rest of the solar system if it is to avoid extinction.
The respected physicist warned of the increasing risk that some kind of natural or man made disaster - such as global warming, or a nuclear war - could destroy the Earth: "It is important for the human race to spread out into space for the survival of the species," he said.
He believes we could have a colony on the moon within 20 years, and an established base on Mars within 40, according to reports, but says that unless we travel to another star system, we "won't find anywhere as nice as Earth".
Various other space scientists and science writers have offered their views. Alan Guth, professor of physics at MIT told The Seattle Times that in the short term he'd rather build an underground base in Antarctica, but said space would be the "ultimate life boat" in 100 years or so.
Meanwhile, Kim Stanley Robinson, author of a series of books about a future settlement on Mars, told New York Daily News: "You want to treat this planet like the only one we have because Mars is poisonous."
Hawking has made similar predictions before. In 2001, when he was promoting his book The Universe in a Nutshell, he warned that a manmade doomsday virus was likely to destroy mankind before the end of the millennium. This time round, he's drumming up interest for a children's book he is planning to co-author with his daughter. ®