"No one would have believed in the last years of the nineteenth century that this world was being watched keenly and closely by intelligences greater than man's and yet as mortal as his own . . . " And so H. G. Wells opened his thrilling The War of the Worlds in 1897. Since then millions of readers have shivered and shrieked at his depiction of a Martian invasion of Earth. The tale has become part of our cultural memory, but Wells didn't tell...