In time, [a Martian] colony would grow to the point of being self- sustaining. When this stage was reached, humanity would have a precious insurance policy against catastrophe at home. During the next millennium there is a significant chance that civilization on Earth will be destroyed by an asteroid, a killer plague or a global war. A Martian colony could keep the flame of civilization and culture alive until Earth could be reverse-colonized from Mars.
![In time, [a Martian] colony would grow to the point of being self- sustaining. When this stage was reached, humanity would have a precious insurance policy against catastrophe at home. During the next millennium there](http://cdn.quoteddaily.com/images/paul-davies/in-time-a-martian-colony-would-grow-to-the-point-of-being-self--sustaining-when-this-stage-was-reached.jpg)