Question

How are halophiles relevant to astrobiology?

Halophiles are part of a group of microbes called extremophiles--tiny organisms able to survive the extremes of the earth’s environment. More specifically, halophiles are microorganisms that flourish in particularly salty (hypersaline) environments. They can be found in conditions of 3% to 30% sodium (NaCl) and may be found in the form of bacteria or multicellular organisms like diatoms and flagellates. Halophiles are relevant to astrobiology in the same manner that all study of extremophiles is relevant to astrobiology--in order to understand the possible boundaries of life’s existence in the universe, we need to first understand the boundaries of life as we know it here on earth. For example, if we discover certain organisms are able to survive a super-saline environment, we may imagine such lifeforms in another super-saline environment elsewhere in the universe—perhaps deep in the subsurface oceans of Europa. For more information on halophile biology, see the non-NASA site, "Halophilic Microorganisms and Their Environments," at http://pasteur.bio.geneseo.edu To see more on the early evolution of life on Earth, check out Penn State’s Astrobiology website at http://psarc.geosc.psu.edu
May 1, 2002