THE HISTORICAL ROOTS OF ASTROBIOLOGY

For thousands of years humans have gazed at the night sky and wondered about the presence of life elsewhere, whether in our solar system or on some other blue planet or body around another star. Such thoughts have found their expression in fiction, scientific missions and religions worldwide. Philosophers and ordinary people have pondered the rise of life on our planet. Creation myths are fundamental to every civilization and culture, and reflect the profound resonance of the question of our origins. Today, astronomers have pushed back our understanding of the origins of the universe to within tiny fractions of microseconds of the big bang. However, science cannot, as yet, offer any complete definition of life, nor point to the time, conditions and mechanisms when organic matter went from nonliving to living.

Just 50 years ago, humans began to extend their presence into space, first with robots and then with humans. As this tentative expansion of our species into other worlds continues, basic questions remain unanswered about the long-term adaptation of living organisms to other environments. We do not know what the effect will be of living for years on Mars, where the pull of gravity is about one-third that of Earth. Astrobiology addresses all these compelling mysteries by embracing the study of the origin, evolution, distribution and future of life in the universe.

Astrobiology, the multidisciplinary science dedicated to the study of life in the universe, has had a profound effect on space exploration world wide. With its roots in the early experiments of Urey-Miller and Exobiology as defined by founding luminaries such as Chuck Klein, the field has gained international status. This paper traces the original impetus for defining the field, its history, and its current status. The beginnings of the NASA Astrobiology Institute are described along with examples of major science results and advances. The influence of the field on research, missions, and policy ranging from early earth studies and NASA’s Mars Exploration Program strategy of “Follow the Water”, to current exploration strategies world-wide, is demonstrated.