This book explores the questions of What, Why, When, How and Where might we might find extra-Terrestrials (a.k.a. Aliens) and their habitats throughout the Universe– and Who might they be? Starting from ourselves and the Earth and eventually speculating about life forms that might span multiple Universes, it provides an accessible introduction to extra-terrestrial life, the search for extra-terrestrial intelligence, and exoplanets. It will enable readers to appreciate, follow and sometimes answer questions on life and planets outside Earth. It details these exciting topics by pondering what comprises an alien life form and what suitable habitats might exist for them inside and out of our solar system. The book also looks ahead to the future and the realities of finding alien life and the possibilities of mankind leaving Earth and living on another planet. This guide is accessible to those without a formal scientific or mathematical background. It will also be of interest to students of astrobiology, astronomy, astrophysics, planets throughout the Universe, the origin and evolution of life-forms beyond the Earth and (perhaps) of the ultimate limits attainable by life in the Universe, who are looking to learn more about those of the same topics which are outside their own specialisms. Key Features: · Combines the exciting topics of extra-terrestrial life, the search for life outside Earth and exoplanets into one accessible guide. · Contains no complex mathematical formula or content. · Authored by a professional educator and a professional and amateur astronomer, with a life-long interest in getting everyone and anyone as fascinated by astronomy and its related subjects as he, himself has been, since discovering the subject in early secondary school. Chris Kitchin is currently Professor Emeritus at the University of Hertfordshire and a freelance writer of astrophysics books. From 1987 to 2001, he was director of the University’s Observatory and from 1996 to 2001, he was also head of the Division of Physics and Astronomy. He took early retirement in 2001 in order to concentrate on his writing. Kitchin has written fourteen single-author books, with several being translated into Chinese, Japanese and Polish and some having multiple editions. He has also contributed to another dozen or so books and he has written hundreds of articles ranging from popular astronomy to specialist research. In 1997, he was awarded the title of Professor of the Public Understanding of Astronomy.