Mars, our closest neighbour, the red planet, has always loomed large in the human imagination. Its bloody colour prompted ancient people to associate it with the God of War. And then, late in the 19th century, the Italian astronomer, Giovani Schiaparelli, noticed lines on the surface of the planet which he called grooves or "canali". This was mistranslated as "canals", and other observers, notably the American Percival Lowell, not only saw the canals but also changing surface patterns that they interpreted as vegetation. The popular belief that Mars was inhabited spread rapidly, aided by the huge international success of The War of the Worlds by H.G. Wells.
Because Mars was assumed to be an older planet, it was similarly assumed that any Martian civilisation must also be older and more advanced, perhaps even decadent, perhaps even in decline and looking with envy upon our own green and fertile world. While astronomy developed an ever more sophisticated view of a world without canals, without vegetation, without life, science fiction persisted in holding to that older view of the planet. From the warring races of Edgar Rice Burroughs's Barsoom to the lush and intriguing world full of different forms of life in Stanley Weinbaum's brilliant short story, "A Martian Odyssey", Mars was always full of life. Indeed, Martian became the common word for any alien, from the panic-inducing invaders of Orson Welles's radio dramatization of "The War of the Worlds" to the strange and magical figure of the 1960s TV comedy, "My Favourite Martian".
Gradually, our scientific knowledge of Mars became inescapable, and a few writers tried to describe a more realistic planet, as in The Sands of Mars by Arthur C. Clarke, but the more romantic image of Mars as ancient civilisation or as frontier territory, persisted. Only with the accelerating Nasa explorations of the planet over the last few decades has the realistic Mars come to dominate Martian science fiction. But now those explorations seem to be bringing us full circle: we are, after all, seeing water channels if not actual canals, and there is now talk of the possibility of life in some form or other. Who knows where Martian science fiction is likely to take us in future, but for now these are some of the best novels (and a couple of novellas) to date about the planet.