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No. 110: Mar-Apr 1997

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Nannobacteria: life on a different scale

Who ever heard of nannobacteria until those tiny, worm-like objects were photographed inside that putative Martian meteorite ALH 84001? It turns out that these very tiny cells (only 0.1 - 0.4 micrometers in diameter) are everywhere on earth, but it seems that virtually no one knows about them. The furor over ALH 84001 has underscored professional and public ignorance of nannobacteria. Some scientists have asserted that bacteria could never be as small as those "objects" seen in the greatly magnified photos of ALH 84001. This claim led R.L. Folk to fire off a letter to Science that began with these two sentences:

"Enough! As one of the discoverers of mineralized nannobacteria on Earth*, I must come to their defense. They are so abundant in samples I have studied that I believe they may make up most of the Earth's biomass."

Folk reports that nannobacteria are found just about everywhere: hot-spring waters, decaying leaves, even blood. Nannobacteria are key players in the earth's surface chemistry, precipitating a host of minerals and acting symbiotically to precipitate organic hard parts.

(Folk, Robert; "In Defense of Nannobacteria," Science, 274:1288, 1996.)

Comment. Ignorance of nannobacteria is not surprising. One needs a scanning electron microscope to see them.

* See: Folk, R.L.; Journal of Sedimen tary Petrology, 63:990, 1993.

From Science Frontiers #110, MAR-APR 1997. 1997-2000 William R. Corliss

Science Frontiers Sourcebook Project Reviewed in:


  • "A sourcebook of unexplained phenomena is therefore a valuable addition to a collection of scientific literature. William R. Corliss has provided this in the past with his source books of scientific anomalies in several subjects, and now he has provided it for astronomy. He has done an excellent job of collecting and editing a large amount of material, taken in part from scientific journals and in part from scientific reporting in the popular or semi-scientific press." -- "The Mysterious Universe: A Handbook of Astronomical Anomalies", reviwed by Thomas Gold, Cornell University, in Icarus, vol.41, 1980

  • "An interesting, systematic presentation of unusual weather [..] This book is recommended for a general audience" --"Corliss, William R., Tornados, Dark Days, Anomalous Precipitation, and Related Weather Phenomena, Sourcebook Project, 1983.", revieweed in Choice, September 1983
  • "..the science is necessarily somewhat speculative, but Corliss's symthesis is based on reputable sources." -- "Corliss, William R. (Compiler). Lightning, Auroras, Nocturnal Lights, and Related Luminous Phenomena" reviwed by Joseph M. Moran, Univ. of Wisconsin in Science Books and Films, Sep/Oct 1983

  • "Before opening the book, I set certain standards that a volume which treads into dangerous grounds grounds like this must meet. The author scrupulously met, or even exceeded those standards. Each phenomenon is exhaustively documented, with references to scientific journals [..] and extensive quotations" -- "Book Review: The moon and planets: a catalog of astronomical anomalies", The Sourcebook Project, 1985., Corliss, W. R., Journal of the Royal Astronomical Society of Canada, Vol. 81, no. 1 (1987), p. 24., 02/1987