All this world is heavy with the promise of greater things, and a day will come, one day in the unending succession of days, when beings, beings who are now latent in our thoughts and hidden in our loins, shall stand upon this earth as one stands upon a footstool, and shall laugh and reach their hands amidst the stars. --H. G. Wells, 1902

Click HERE to go to The Astronomy Place, your link to the Life in the Universe companion web site This site contains resources for students and instructors.

Table of Contents

Praise for Life in the Universe:
This textbook combines the explosion in our knowledge of life on Earth with the latest findings about solar system environments, extrasolar planets, and SETI. It is the right text at the right time for teaching some of the fastest-moving topics in science.---Chris Chyba, Carl Sagan Chair for the Study of Life in the Universe, SETI Institute, and Stanford University

A thoughtful and well-written tour through the emerging field of astrobiology. Many university educators will want to use this book.---Professor James Kasting, Penn State University

... well-written, very interesting, and covers very well the broad sweep of sciences included in astrobiology.---Stacy Palen, University of Washington

Very well written and accessible... one of the best expositions of the subject I have ever seen. The end-of-chapter questions are extensive, thought provoking, and pitched at just the right level.--- Sukanta Bose, Washington State University

... the level of reading is excellent throughout... the material is very easy to follow. The authors know their stuff and explain it very well. Unlike many textbooks nowadays, it's well written and thought provoking...---Juan Cabanela, Haverford College

... very readable and compelling. Key topics are explained in such a way that my non-scientist students will really understand them.--- David Thomas, Lyon College

... asks lots of good questions throughout the text... should encourage the student to really think about this exciting subject.---Harold Geller, George Mason University

The finest text on the subject I have ever encountered... it should become a classic.---Wayne Anderson, Sacramento City College

Life in the Universe:
Few questions have so inspired humans through the ages as the mystery of whether we are alone in the universe. Many ancient Greek philosophers were confident that intelligent beings could be found far beyond Earth. When the first telescopes were trained on the Moon in the 17th century, some eminent astronomers interpreted lunar features as proof of an inhabited world. Barely a century ago, belief in a civilization on Mars became so widespread that the term "martian" became synonymous with "alien." But despite this historical interest in the possibility of extraterrestrial life, until quite recently few scientists devoted effort to understanding the issues that surround it, let alone to making a serious search for life.

In the past couple decades, however, a remarkable convergence of biology, geology, astronomy, and other sciences has suddenly put the issue of extraterrestrial life on the forefront of research. Advances in understanding of the origin of life on Earth are helping us predict the conditions under which life might arise elsewhere. Discoveries of microbes thriving under extreme conditions (at least by human standards) on Earth have raised hopes that life might survive even in some of the harsh environments found elsewhere in our own solar system. Proof that planets exist around other stars--first obtained only in the 1990s--has provided added impetus to the study of the conditions that might allow for life in other star systems. And technological advances are making it possible for us to engage in unprecedented, large-scale scrutiny of the sky for signals from other civilizations, spurring heightened interest in the search for extraterrestrial intelligence (SETI). Perhaps most important, scientists have found intrinsic value in the interdisciplinary study of issues relating to the search for life beyond Earth--value that remains whether or not the search is ultimately successful.

Given the intense research efforts being undertaken by the scientific community and the long-standing public fascination with the search for life, it should be no surprise that the study of life in the universe --also known as astrobiology--has become one of the most publicly visible sciences. But as is often the case, scientific discovery is moving much more quickly than innovations in education. As a result, most people have had little opportunity to learn about the remarkable scientific adventure now underway to answer fundamental questions about life on Earth and beyond. This book aims to help improve this situation, by offering an introduction to the broad science of astrobiology in a way that is fairly comprehensive but still accessible to readers with little or no scientific training.

Note that, although we have written this book in a format that makes it especially suitable as a textbook for introductory astrobiology courses, it is designed to be of interest to anyone with a desire to learn about the current state of research in the exciting science of life in the universe. No special scientific training or background is assumed, and all necessary concepts of science are reviewed as they arise. If you have a basic high school education and a willingness to learn, you are capable of understanding every topic covered in this book.

Table of Contents

PART I INTRODUCING ASTROBIOLOGY

1. A Universe of Life?
2. The Science of Life in the Universe

PART II LIFE ON EARTH

3. The Nature of Life
4. The Geological History of the Earth
5. The Origin and Evolution of Life on Earth

PART III LIFE IN THE SOLAR SYSTEM

6. Searching for Life in Our Solar System
7. Mars
8. Life on Jovian Moons
9. The Nature and Evolution of Habitability

PART IV LIFE AMONG THE STARS

10. The Search for Habitable Worlds
11. The Search for Extraterrestrial Intelligence
12. Interstellar Travel
13. The Fermi Paradox
14. Contact--Implications of the Search and Discovery