Stephen Hawking: 'Humans need to leave Earth'

It's time for humans to take on their next trip to the moon, according to Stephen Hawking. Speaking at the science festival Starmus Festival, the physicist warned humankind must prepare for a cosmic exodus that will happen within 500 years. “Spreading out may be the only thing that saves us from ourselves. I am convinced that humans need to leave Earth.” Hawking urged countries to coordinate to create a plan a moon colony with the next 30 years, and prepare to reach Mars in the next 15.