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No. 118: Jul-Aug 1998

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Broadside Against Small Icy Comets

In a late-1997 issue, Geophysical Research Letters published a group of five papers that detailed five different lines of evidence that are inconsistent with the claim by L.A. Frank and J.B. Sigwarth that the earth is bombarded daily by 30,000 house-size icy comets. If such bombardment has really been occurring, scientists would have to rethink the origins of the earth's oceans, terrestrial life, and the formation of the solar system. No wonder the icy-comet hypothesis is strongly challenged!

Three of the more interesting points made by this group of papers are as follows:

  1. Our moon could not escape the icy-comet bombardment. Roughly 1,000 craters 50 meters in diameter and splashes of debris 150 meters in diameter must occur each. There is no evidence that the moon is thus afflicted.
  2. Comets also carry the noble gases argon, krypton, and xenon. These gases should accumulate in the atmosphere as the comets disintegrate. The amounts of these gases actually measured are 10,000 times less than those the postulated bombardment would produce.
  3. The icy comets should break up near the earth and produce clouds of ice crystals. Sunlight reflected from such 30-ton clouds would be brighter than Venus and easily visible before they disperse. Such objects are rarely seen, implying that small icy comets do not exist in the numbers claimed.

Preceding this series of five papers is one by Frank and Sigwarth in which they describe their detection of atomic oxygen trails near earth. These they attribute to small icy comets.

(Various; "Looking for Small Comets -- None Found," Geophysical Research Letters, 24:2429++, 1997.)

From Science Frontiers #118, JUL-AUG 1998. 1998-2000 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