Prof Stephen Hawking has called for leading nations to send astronauts to the Moon by 2020.
Prof Hawking said that the goal would re-ignite the space programme, forge new alliances and give humanity a sense of purpose.
Spreading out into space will completely change the future of humanity Prof Stephen Hawking.
"Spreading out into space will completely change the future of humanity," he said.
"I hope it would unite competitive nations in a single goal, to face the common challenge for us all.
Image copyright Neil A. Armstrong Image caption Return of the Moon landings would give humanity "a sense of purpose".
Prof Hawking explained that human space travel is essential for the future of humanity precisely because the Earth was under threat from climate change as well as diminishing natural resources. »