Stephen Hawking says humans are turning into "cosmic sloths," watching the universe go by without leaving the comfort of our own home, and it's time to do something about it, the Evening Express reports. "Spreading out may be the only thing that saves us from ourselves," the BBC quotes Hawking as saying during the Starmus Festival in Norway. Hawking says countries should work together to send astronauts to the moon by 2020, send astronauts to Mars by 2025, and build a moon base in the next three decades. After that, he gives humanity 200 to 500 years to travel beyond the solar system in search of a new home. “Human colonization on other planets is no longer science fiction," Hawking says. "It can be science fact."
And humanity needs to figure that out sooner rather than later. Hawking has said humans only have 100 or so years left on Earth as they face extinction from climate change, nuclear war, and more, USA Today reports. In addition, the Earth is running out of both space and natural resources. Hawking says the endeavor to find a new home would "elevate humanity." "Whenever we make a great new leap, such as the Moon landings, we bring people and nations together, usher in new discoveries and new technologies," he says. The European Space Agency and Russia are working together on a plan to replace the International Space Station with a moon base in 2024. And NASA is currently focused on sending astronauts to Mars sometime in the 2030s. (Read more Stephen Hawking stories.)