A permanent base on Mars would have a number of advantages beyond being a bonanza for planetary science and geology. If, as some evidence suggests, exotic micro-organisms have arisen independently of terrestrial life, studying them could revolutionise biology, medicine and biotechnology. – Paul Davies
Perhaps the best motivation for going to Mars is political. It is obvious that no single nation currently has either the will or the resources to do it alone, but a consortium of nations and space agencies could achieve it within 20 years. – Paul Davies