"The colored sands in their patterns, the fluted and scalloped canyon walls, the volcanoes rising right through the sky, the rubbled rock of the chaotic terrain, the infinity of craters, ringed emblems of the planet's beginning. . . . The visible language of nature's mineral existence.

"Mineral; not animal, nor vegetable, nor viral. It could have happened but it didn't. There was never any spontaneous generation out of the clays or the sulphuric hot springs; no spore falling out of space, no touch of a god; whatever starts life (for we do not know), it did not happen on Mars. Mars rolled, proof of the otherness of the world, of its stony vitality." (Kim Stanley Robinson, Red Mars)

There are no little green men on the Mars of science fiction writer Kim Stanley Robinson. His is the Mars of the satellite photos and geologic surveys of NASA's Mariner and Viking missions...