No matter how we turn it around, the fate of the Earth is sealed: It has been certain for many years that in a billion years at the latest, the sun will have become so hot in its interior in the course of the advancing fusion processes, that all water on earth will evaporate and all life will end. Presumably, however, the end will come much sooner. The next impact of an asteroid, which led to the extinction of the dinosaurs, is also statistically overdue. Only the next time, humans would be affe...