Mars could have water and life. This is the astonishing information now coming back from the Mariner 9 orbiting probe. Patrick Moore discusses the evidence in the latest photographs with a geologist, Dr Peter Cattermole, and explains the significance of these revelations. Have you a question about astronomy you would like to ask Patrick Moore? In the next Sky at Night on 27 March he will answer as many as he can in the time available. Send your questions - on a postcard - to: The Sky at Night, [Address removed]. Sorry, Patrick Moore cannot reply to questions not included in the programme.