Astrobiology is the scientific discipline that focuses on the origin, evolution and distribution of life in the universe. Most efforts aiming at understanding the origin of life on Earth, and the possibility that life might exist elsewhere, are directed to the study of microorganisms. This is so because on Earth, microorganisms are the most abundant and widespread forms of life, and are seemingly able to colonise virtually every environment that can support life. Furthermore, small and relatively simple cells are more likely to originate first on a planet than large and complex multicellular organisms, and are also more likely to be transported from one planet to another in the process of panspermia. Hence the term Astro(micro)biology. In this article I introduce and summarise the main fields of research in Astro(micro)biology.

Key Concepts:

  • The study of life in the Universe requires an interdisciplinary approach.

  • Mars is the prime target for the search for life beyond the Earth.

  • The primary focus of planetary exploration is concerned with planets having liquid water.

  • Terrestrial analogue environments share physical, chemical, geological, mineralogical and any other type of environmental similarity with another planetary body.

  • Meteorites represent the main source of extraterrestrial material available to scientist.

  • Extrasolar planets are a likely candidate to provide the first evidence of life outside the Earth.

Keywords: life; universe; planets; moons; mars; atacama; antarctica; space; astrobiology; microorganisms

Figure 1.

Panorama image of Chryse Planitia on Mars taken by the Viking Lander 1. Image credit: NASA/JPL.

Figure 2.

(a) Panorama of the Atacama Desert, Chile (Photograph courtesy of Jacek Wierzchos). (b) Aerial picture of University Valley, Antarctica (Photograph courtesy of Dale T. Andersen).

Figure 3.

(a) Halite (sodium chloride) knob from the Atacama Desert with endolithic colonisation (green). (b) Light microscopy image of the cell colonies (arrows) inside the halite.

Figure 4.

Payload of the PharmaSat nano‐satellite. Photograph courtesy of NASA/ARC/Christopher Beasley.

Figure 5.

The ALH84001 Martian meteorite. Scale bar represents 1 cm.



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Further Reading

Lunine JI (2005) Astrobiology. A Multi‐Disciplinary Approach. San Francisco: Pearson Addison Wesley.

Sullivan WT III and Barros JA (eds) (2007) Planets and Life. The Emerging Science of Astrobiology. Cambridge, UK: Cambridge University Press.

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How to Cite close
Davila, Alfonso F(Sep 2010) Astromicrobiology. In: eLS. John Wiley & Sons Ltd, Chichester. [doi: 10.1002/9780470015902.a0021899]