Freeman Dyson at the NYRB:
Farming is an art that achieved success after innumerable failures. So it was in the past and so it will be in the future. Any successful human settlement in space will begin as the Polynesian settlements in the Pacific islands began, with people bringing pigs and chickens and edible plants on their canoes, along with the skills to breed them. The authors of Beyond Earth imagine various possible futures for human settlement in various places, but none of their settlers resemble the Polynesians.
Jon Willis’s All These Worlds Are Yours describes the possibilities for alien forms of life to exist in remote places and the practical steps we might take to discover them. The places that are discussed are the planet Mars, the moon Europa of Jupiter, the moons Titan and Enceladus of Saturn, and the newly discovered planets orbiting around other stars. Willis considers Enceladus to be the most promising place for us to look for evidence of life. Enceladus has active geysers spraying jets of salt water and steam into space from hot spots on its surface. The geysers must originate in an underground system of channels connected to a warm deep ocean in which life might be flourishing. To study possible traces of life in microscopic detail, we should send an unmanned spacecraft through the jets to collect samples of droplets and vapor and bring the samples back to Earth to be examined at leisure in a well-equipped laboratory.