Life elsewhere in the universe is a staple of science fiction but it might seem to be pure speculation. However, 'An introduction to Astrobiology' shows that there is some real science behind the search for extraterrestrial life. It's written as an undergraduate textbook for The Open University, but does not require much in the way of scientific background - the authors are careful to explain the science needed at each stage. With plenty of pictures and diagrams, together with exercises for the reader with full solutions, it makes an excellent resource for those wanting to improve their knowledge of this subject beyond the sci-fi stage.
The book starts in our solar system, looking at the development of life on Earth and going on to discuss the search for life on other planets, such as Mars. The possibility of life on the satellites of Jupiter and Saturn is also examined, and there is a chapter devoted to Titan, although the book was written before the Huygens probe landed, and so doesn't have the latest results. The later chapters of the book examine the possibility of finding life outside the solar system, reviewing the recent discovery of exoplanets and how future telescopes may detect the signs of life. The final chapter looks at the search for extraterrestrial intelligence via radio signals.