Mission Of Gravity

Hard science fiction in its purest form didn't have villains; the implacable laws of the universe were enemy enough for anyone. After all, who needs enemies when you're faced with an oblate planet where gravity is 3g at the equator but a massively crippling 700g at the pole? That's what Hal Clement created with the planet Mesklin in his greatest novel, Mission of Gravity. A human probe has fallen at the pole, and team member Charles Lackland has to get it back. But he can scarcely stand at the equator, so he has to recruit a local trader to do the job for him. This is Barlennan, a centipede-like being who is terrified of even small heights, because any fall in 700g would be fatal. The story very simply tells of his mission, and the ways he must overcome the simple, practical obstacles that nature puts in his way. Why it's on the list: This is the definitive example of worldbuilding in science fiction. Clement carefully worked out the physical characteristics of his world, then wrote a story simply designed to explore those characteristics. As a story in which we slowly come to recognise the truly alien, an environment that is incredibly hostile, the novel is surprisingly tense and full of interest.