Renowned theoretical physicist Stephen Hawking has warned humanity has only 1,000 years left on Earth, and it is high time they intensified efforts to find another planet to live on.
This is because Earth is no longer a safe place as risks of mass extinction are mounting.
Addressing students at the Oxford University Union, Hawking said the situation on Earth for humans will remain the same even if mankind survives the brunt of artificial intelligence, climate change and the threat of nuclear terrorism in the coming century.
"I don't think we will survive another 1,000 years without escaping beyond our fragile planet," he added.
Hawking's concerns over Earth are exacerbated by a "cataclysmic end" of the planet that is hastened by activities of humans that are depleting the resources of Earth at alarming rates.
"We must ... continue to go into space for the future of humanity," the 74-year-old Cambridge professor said.
Hawking added that the only thing that could salvage mankind is establishing colonies in other parts of the solar system.
At the same time, Hawking does not see human colonies on Mars as a viable option for another 100 years or so.
Despite the gloomy outlook, Hawking said he is still optimistic about 2016 as a "glorious time to be alive and doing research in theoretical physics."
Stephen Hawking's Recurring Concern
The Oxford speech is yet another iteration of Hawking's belief that Earth's days are numbered and humans need to figure out where their species will be living next.
In a lecture at London's Royal Institution early this year, Hawking also warned that nuclear war, global warming, and genetically engineered viruses are some of the major threats faced by humanity.
Sounding skeptical about artificial intelligence, the professor said it could either be "the best or worst thing ever to happen to humanity."
Hawking advocated that the only solution left for mankind to secure them is by colonizing another planet. He exhorted the university students to "stay curious" and "look up to the stars and not down at your feet."
A decade ago, Hawking told the BBC that, sooner or later, disasters like an asteroid collision or nuclear war would wipe out mankind.
"But once we spread out into space and establish independent colonies, our future should be safe."
In 2010, Hawking announced that humanity's future "must be" in space. He said the same thing in his remarks delivered at Sydney's Opera House in 2015.
"For the future of humanity, I want to encourage public interest in space."