Astrobiology

Astrobiology is the study of the origins, evolution, distribution, and future of life in the Universe. Its goals include the study of life on Earth and the search for life beyond Earth. It addresses three fundamental questions: How does life begin and evolve? Is there life beyond Earth and how can we detect it? What is the future of life on Earth and the Universe?

Astrobiology requires fundamental concepts of life and habitable environments that will help scientists to recognize biospheres that might be quite different from the Earth's one. It embraces the search for potentially inhabited planets beyond the Solar System, the exploration of Mars and the outer planets, laboratory and field investigations of the origins and early evolution of life, and studies of the potential of life to adapt to future challenges, both on Earth and in space.

Astrobiology is multidisciplinary in its content and interdisciplinary in its execution. Its success depends critically upon the close coordination of diverse scientific disciplines and programs, including space missions. Interdisciplinary research is needed that combines Molecular Biology, Ecology, Planetary Science, Astronomy, Information Science, Space Exploration, and related disciplines. The broad character of Astrobiology compels scientists to strive for the most comprehensive and inclusive understanding of biological, planetary and cosmic phenomena.

Domains of Investigation and Goals of Research

Astrobiology encompass seven key domains of investigation:

• the nature and distribution of habitable environments in the Universe;

• the past or present habitable environments, prebiotic chemistry and signs of life elsewhere in our Solar System;

• how life originates from cosmic and planetary precursors;

• how past life on Earth interacted with its changing planetary and Solar System environment;

• the evolutionary mechanisms and environmental limits of life;

• the principles that will shape the future of life, both on Earth and beyond;

• how to recognize signatures of life on other worlds and on early Earth.

To these domains corresponds respectively the following research goals:

• determine the potential for habitable planets beyond the Solar System, and characterize those that are observable;

• determine any chemical precursors of life and any ancient habitable climates in the Solar System, and characterize any extinct life, potential habitats, and any extant life on Mars and in the outer Solar System;

• perform observational, experimental and theoretical investigations to understand the general physical and chemical principles underlying the origins of life;

• investigate the historical relationship between Earth and its biota by integrating evidence from both the geologic and biomolecular records of ancient life and its environments;

• determine the molecular, genetic, and biochemical mechanisms that control and limit evolution, metabolic diversity, and acclimatization of life;

• elucidate the drivers and effects of ecosystem change as a basis for projecting likely future changes on time scales ranging from decades to millions of years, and explore the potential for microbial life to adapt and evolve in environments beyond its planet of origin;

• identify biosignatures that can reveal and characterize past or present life in ancient samples from Earth, extraterrestrial samples measured in situ, samples returned to Earth, remotely measured planetary atmospheres and surfaces, and other cosmic phenomena.

Investigative Efforts

Astrobiologists try to accomplish their research goals by directing their efforts to the following objectives: