As I write this short preface, the red orb of Mars is high in the eastern sky, and is brighter than it has been for many years. Last night my telescope again revealed the strange polar hood which is a feature of the planet at this time in its cycle. Because of its current prominence in the night sky, it is a very appropriate time to bring together and reappraise what we know of Mars and look forward to the next wave of planetary exploration. The initial notion of writing a book about Mars ...