Category:	Science and Technology
Domain:	Space Sciences, Biology and Biotechnology
Keywords:	Space science & Astronomy - evolution, origins, extraterrestrial life
Outlook:	Multidisciplinary efforts by astrobiologists may increase our understanding of the origins of life on this planet and could result in finding biospheres beyond Earth.
Summary Analysis:	Astrobiology, is the study of life in the universe. The field is driven by fundamental questions that have fascinated scientists and lay people for millennia: Where did we come from? Where are we going? Are we alone? Astrobiology is necessarily a multidisciplinary field, drawing from astronomy, genomics, molecular biology, information technology, geology, paleontology, chemistry, physics, astronomy, and planetary science. Through collaborative efforts among these disciplines, scientists hope to understand the origin, evolution, and distribution of life. Astrobiologists start from the assumption that only by identifying the 'conditions necessary for life to emerge' can scientists know how and where to look for life elsewhere in the universe, especially when habitable environments may be very different from our own home. Some scientists, notably Jack Cohen and Ian Stewart, reject the term 'astrobiology' and the whole astrobiology programme along with it. For them, talk of 'conditions necessary for life' is both parochial and unimaginative. They dismiss astrobiology as, "the science of Earthlike planets supporting Earthlike life". In place of astrobiology, they speak about 'xenobiology' or 'xenoscience' -- a science that restricts itself less than astrobiology, does not presume to be able to determine the conditions necessary for life and absolutely refuses to discuss 'habitable zones' (regions around stars that are conducive to Earth-type life -- not to hot nor too cold). In general use, the terms are interchangable, but the existence of an emerging coherent field (astrobiology) and a radical opposition to the growing consensus (xenobiology) is significant. Because scientists have yet to prove the existence of life on other planets, most astrobiology is done on Earth. For example, researchers have been surprised to find life in such extreme environments as incredibly hot volcanic vents in the deep ocean, icy Antarctic lakes, and highly acidic water. These are the kinds of environments that may harbour life elsewhere in the universe, and studying life forms that thrive there opens our eyes to the robustness and adaptability of life. The search for life in the universe continues in biology laboratories too. All life we know about has a similar biochemical basis but it is currently unknown if DNA, etc. is a necessary condition for all life, or just an 'accident' of life on Earth. Attempts to create synthetic life forms will help answer this question. Advances in theoretical biology precipitated by new mathematical approaches are also helping to set the parameters for the search for life beyond Earth. In our own solar system, scientists have found evidence of water on both Mars and Jupiter's moon Europa. The existence of water is a necessary condition of all life we know, so locations with water may be a good place to start the search for life. In the coming decades, astrobiologists may very well determine whether life exists there or did in the past. Meanwhile, astronomers continue to discover planets outside our solar system, and one of their goals is to find Earth-like planets with chemistry conducive to life as we know it. The NASA Astrobiology Roadmap outlines seven scientific goals that are expected to be the most fertile ground for exploration in the coming years: Understand the nature and distribution of habitable environments in the universe Explore for past or present habitable environments, prebiotic chemistry, and signs of life elsewhere in our solar system Understand how life originates from cosmic and planetary precursors Understand how past life on Earth interacted with its changing planetary and solar system environment Understand the evolutionary mechanisms and environmental limits of life Understand the principles that will shape the future of life, both on Earth and beyond Determine how to recognize signatures of life on other worlds and on early Earth

	Implications:	Potential to discover extraterrestial life Better understanding of the origins of life on Earth, past extinctions, and the possible future of life on this planet Better understanding of the impact of space environments on human physiology and our own possible future in space Potential for medical applications of astrobiology tools such as lab-on-a-chip and other bio-assays
	Early Indicators:	1977 discovery of life in hydrothermal vents Development by James Lovelock of the Gaia Hypothesis from an attempt to determine if there was life on Mars by studying the planet's atmosphere Discovery of more than 150 exoplanets Discovery of evidence of liquid water on Europa and possibly Mars Ongoing development of plans for a manned mission to Mars before midcentury Founding in 1998 by US NASA of the NASA Astrobiology Institute (NAI), consisting of hundreds of astrobiologists at more than a dozen institutions around the US, from UC Berkeley to Pennsylvania State University to the SETI Institute Launching of similar large-scale efforts around the world through such NASA partners as the Astrobiology Society of Britain, Australian Centre for Astrobiology, and the Centro de Astrobiologia Founding of the International Journal of Astrobiology at Cambridge University Development of A-life (simulated organisms that live in virtual environments) Application of cellular automata to theoretical biology
	What to Watch:	New terrestrial planets like Mars and Earth are discovered.
	Parallels/Precedents:	Deep-sea exploration
	Enablers/drivers:	Continued fostering of multidisciplinary science projects Renewed interest in space exploration, driven by a desire to know if there's life 'out there' Development of new biological, chemical, and geological tools for analysing samples brought back from space and extreme environments Development of increasingly advanced telescopes, both terrestrial and space-based Advances in A-Life that inform theoretical biology Development of in the laboratory of synthetic micro-organisms Development of synthetic organisms that use a mechanism other than DNA or RNA to encode information for reproduction
	Leaders:	Institutions and Organisations: US NASA (Astrobiology Institute [link], PlanetQuest planet-finding effort [link], Mars Exploration Program [link], astrobiology missions [link]) ESA (European Space Agency, Aurora Exploration Programme [link]) Centro de Astrobiologia [link] Astrobiology Society of Britain [link] Australian Centre for Astrobiology [link] Groupement de Recherche en Exobiologie [link] European Exo/Astrobiology Network Association [link] British Antarctic Survey [link] Natural Environment Research Council (UK) [link] British Interplanetary Society [link] Open University (UK) space and planetary group [link] SETI group of International Academy of Astronautics [link] Cardiff Centre for Astrobiology [link] British National Space Centre [link]
	Figures:
	Sources:	"NASA Astrobiology Institute" NASA Astrobiology Institute [link] Astrobiology Magazine [link] "The Astrobiology Web" The Astrobiology Web [link] Ferris, Timothy. "Life Beyond Earth." PBS [link] "Text of a Speech by NASA Administrator Daniel S. Goldin About Astrobiology." NASA. 18 May 1999 [link] Pescovitz, David. 2004. "From Crime Scene Clues To Life On Mars" ScienceMatters@Berkeley Vol. 1, Issue 6. [link] Jack Cohen and Ian Stewart, 2004, What does a Martian Look Like?, London: Ebury Press. [link] ESA Astrobiology Page http://www.esa.int/esaCP/SEM7QR39ZAD_Life_0.html Jean Heidmann, SETI in Europe, Environment Observation and Climate Modelling Through International Space Projects. Space Sciences with Particular Emphasis on High-Energy Astrophysics p 165-166, ESA 1992 Jill Tarter, The Search for Extraterrestrial Intelligence, Ann Rev Astron and Astrophys, 2001, 39, 511-548 Wynn-Williams, D D, Why astrobiology needs collaboration, Astronomy & Geophysics 42 (5), 5.20-5.21, 2001

	At A Glance:	When:	21–50 years +
		Where:	Global
		How Fast:	Years
		Likelihood:	Low
		Impact:	High
		Controversy:	High

Related Outlooks:

Posted at Jan 05/2007 09:38AM:
NO, Jack Cohen and Ian Stewart speak about xenoscience and *not* about xenobiology. See their book entitled What Does a Martian Look Like? (Evolving the Alien). Ebury Press, 2002, p. 6.: "There is a problem with the word 'xenobiology'...: it tacitly assumes that the way to make progress is to focus on the _biology_ of aliens. In reality, the whole area has to be interdisciplinary. The biology is intimately entwined with the planetary science, and controversely. So... we will argue the case for a much wilder kind of thinking - which, for ease of reference, we'll call 'xenoscience'". Zoltan Galantai

Posted at Jan 05/2007 11:51AM:
Thanks-- I've changed the line to 'xenobiology' or 'xenoscience,' as both terms are currently in use.