Worlds Without End
As recently as the early 1990s, our Solar System contained the only planets known to us and Earth seemed the only possible haven for life. To say that the last three decades have changed this outlook would be a massive understatement. Today, thanks to an array of ground- and spacebased telescopes and the individuals who lobbied for, built, operated and analysed data from them, over 5,000 planets have been identified beyond our Solar System. Of these, almost 200 are rocky, terrestrial planets like Earth and many are at a favourable distance from their star to harbour liquid water – a requirement for life as we know it and hence used as an indicator of habitability. Indeed, observations of our stellar neighbourhood so far point to there being more planets than stars. This means we might expect several hundred billion planets in our own Galaxy and perhaps similar numbers in other galaxies across the Universe. With so many planets out there, is Earth really that unique after all?
This question, and ultimately the implications of its answer for humanity’s survival, is at the very heart of Worlds Without End. Chris Impey takes the reader on an expertly navigated whirlwind tour of the fast-paced field of exoplanets. Early chapters describe the methods and telescopes used to discover exoplanets and the different types that have been found so far, while later chapters consider whether they might be habitable (or indeed already inhabited), how we might determine this with new telescopes and future spacecraft, which ones we should focus such a search on, and what technological developments are needed to visit and ultimately colonise them. The damage we are doing to Earth and the consequences we are facing are underlying themes visited at several points throughout and provide the motivation to search for the new home we may eventually need. Worlds Without
End is a fascinating read that is crammed with information. Helpful illustrations and insightful quotations pepper the text and have been skilfully crafted into a captivating and accessible narrative capable of bringing all readers up to speed on this exciting and quickly evolving topic. ★★★★★