title: Astrobiology: exploring the origins, evolution, and distribution of life in the Universe.
abstract: The search for the origins of life and its presence beyond Earth is strengthened by new technology and by evidence that life tolerates extreme conditions and that planets are widespread. Astrobiologists learn how planets develop and maintain habitable conditions. They combine biological and information sciences to decipher the origins of life. They examine how biota, particularly microorganisms, evolve, at scales from the molecular to the biosphere level, including interactions with long-term planetary changes. Astrobiologists learn how to recognize the morphological, chemical, and spectroscopic signatures of life in order to explore both extraterrestrial samples and electromagnetic spectra reflected from extrasolar planets.
authors.affiliation: Ames Research Center, NASA, Moffett Field, California 94035-1000, USA. ddesmarias@mail.arc.nasa.gov
authors.forename: D J
authors.initials: DJ
authors.lastname: Des Marais
authors.forename: M R
authors.initials: MR
authors.lastname: Walter
mesh_terms: D005075:Biological Evolution; D004783:Environmental Microbiology; D019419:Evolution, Planetary; D018559:Exobiology; D005118:Extraterrestrial Environment; D018535:Mars; D019110:Meteoroids; D000069497:Origin of Life; D016082:Solar System