This book investigates the idea that the distant future evolution of our Sun might be 'controlled' (literally, asteroengineered) so that it maintains its present–day energy output rather than becoming a highly luminous and bloated red giant star – a process that, if allowed to develop, will destroy all life on Earth. The text outlines how asteroengineering might work in principle and it describes what the future solar system could look like. It also addresses the idea of asteroengineering as a galaxy–wide imperative, explaining why the Earth has never been visited by extraterrestrial travellers in the past.