"A fascinating and useful handbook to both the science and science fiction of extraterrestrial life. Cohen and Stewart are amusing, opinionated, and expert guides. I found it a terrific and informative piece of work-nothing else like it!" -Greg Bear "I loved it." -Larry Niven "Ever wonder about what aliens could be like? The world authority is Jack Cohen, a professional biologist who has thought long and hard about the vast realm of possibilities. This is an engaging, swiftly moving study of alien biology, a subject with bounds and constraints these authors plumb with verve and intelligence." -Gregory Benford "A celebration of life off Earth. A hearteningly optimistic book, giving a much-needed antidote to the pessimism of astrobiologists who maintain that we are alone in the universe-a stance based on a very narrow view of what could constitute life. A triumph of speculative nonfiction." -Dougal Dixon, author of After Man: A Zoology of the Future

What would life on other planets look like? Forget the little green men, alien life is likely to be completely unrecognisable -we haven't even discovered all the life on our own planet. This visionary book offers some of the most radical but scientifically accurate thinking on the possibility of life on other planets ever conceived. Using broad principles of Earthly biology and expanding on them laterally, Cohen and Stewart examine what could be out there. Redefining our whole concept of what 'life' is, they ask whether aliens could live on the surface of a star, in the vacuum of space or beneath the ice of a frozen moon. And whether life could exist without carbon or DNA -or even without matter at all. They also look at 'celebrity aliens' from books and films -most of which are biologically impossible. Jack Cohen is an 'alien consultant' to many writers, advising what an alien could and couldn't look like. (E. T. go home -you do not pass the test). But this book is as much about the latest discoveries in Earthly biology as well as life on other planets. It's a serious yet entertaining science book, as you'd expect from the bestselling authors of THE SCIENCE OF DISCWORLD.

Award-winning journalist Stephen Petranek says humans will live on Mars by 2027. Now he makes the case that living on Mars is not just plausible, but inevitable. It sounds like science fiction, but Stephen Petranek considers it fact: Within twenty years, humans will live on Mars. We’ll need to. In this sweeping, provocative book that mixes business, science, and human reporting, Petranek makes the case that living on Mars is an essential back-up plan for humanity and explains in fascinating detail just how it will happen. The race is on. Private companies, driven by iconoclastic entrepreneurs, such as Elon Musk, Jeff Bezos, Paul Allen, and Sir Richard Branson; Dutch reality show and space mission Mars One; NASA; and the Chinese government are among the many groups competing to plant the first stake on Mars and open the door for human habitation. Why go to Mars? Life on Mars has potential life-saving possibilities for everyone on earth. Depleting water supplies, overwhelming climate change, and a host of other disasters—from terrorist attacks to meteor strikes—all loom large. We must become a space-faring species to survive. We have the technology not only to get humans to Mars, but to convert Mars into another habitable planet. It will likely take 300 years to “terraform” Mars, as the jargon goes, but we can turn it into a veritable second Garden of Eden. And we can live there, in specially designed habitations, within the next twenty years. In this exciting chronicle, Petranek introduces the circus of lively characters all engaged in a dramatic effort to be the first to settle the Red Planet. How We’ll Live on Mars brings firsthand reporting, interviews with key participants, and extensive research to bear on the question of how we can expect to see life on Mars within the next twenty years.

The search for life on Mars—and the moral issues confronting us as we prepare to send humans there Does life exist on Mars? The question has captivated humans for centuries, but today it has taken on new urgency. As space agencies gear up to send the first manned missions to the Red Planet, we have a responsibility to think deeply about what kinds of life may already dwell there—and whether we have the right to invite ourselves in. Telling the complete story of our ongoing quest to answer one of the most tantalizing questions in astronomy, David Weintraub grapples with the profound moral and ethical questions confronting us as we prepare to introduce an unpredictable new life form—ourselves—into the Martian biosphere. Now with an afterword that discusses the most recent discoveries, Life on Mars explains what we need to know before we go.

"A fascinating and useful handbook to both the science and science fiction of extraterrestrial life. Cohen and Stewart are amusing, opinionated, and expert guides. I found it a terrific and informative piece of work-nothing else like it!" -Greg Bear "I loved it." -Larry Niven "Ever wonder about what aliens could be like? The world authority is Jack Cohen, a professional biologist who has thought long and hard about the vast realm of possibilities. This is an engaging, swiftly moving study of alien biology, a subject with bounds and constraints these authors plumb with verve and intelligence." -Gregory Benford "A celebration of life off Earth. A hearteningly optimistic book, giving a much-needed antidote to the pessimism of astrobiologists who maintain that we are alone in the universe-a stance based on a very narrow view of what could constitute life. A triumph of speculative nonfiction." -Dougal Dixon, author of After Man: A Zoology of the Future