Only two hundred years left

That's the time Manhood has left before the Earth been destroyed ( by nuclear disaster and/or accident.)
It's the qualified opinion espressed by astrofisicist Stephen Hawking in an interview released to a Webchannel.
The great scientist also believes that Humanity needs to colonize the space, in order to survive to his own destruction.
He added that crisis such that suffered in 1963, at the time Russian and American risk to face each other in a nuclear world war for Cuban missils, will have place again and again in the next history of men's relation, making the risk of selfdestruction.
But if men succeed in avoiding such an event in the next two hundred years, they will be able to conquer the space.

To learn more on that:
http://www.dailymail.co.uk/sciencetech/article-1301482/emailArticle.html