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No. 49: Jan-Feb 1987

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Halley's confounding fireworks

"Serendipitous discovery in science so often comes as a surprise, even when it might reasonably be expected. Such was the case with Comet Halley in the wake of an observation program that dwarfed all preceding efforts. The surprises included sudden outbursts in the presumably steady vaporization of its icy nucleus and a periodic, complex pulsation of the comet's brightness. Whether this pulsation reflects the rotation of the nucleus, or some still unimagined phenomenon became a controversial focus of the recent meeting on the Exploration of Halley's Comet in Heidelberg."

Some of the data presented and some of the attendees at this conference supported a rotational period of 2.2 days; others favored 7.4 days; a few liked a 2.2-day period with a 7.4-day wobble superimposed.

(Kerr, Richard A.; "Halley's Confounding Fireworks," Science, 234:1196, 1986. Also: Campbell, Philip; "How Fast Does Halley Spin?" Nature, 324:213, 1986.)

Halley's fireworks (visible outbursts) have also stimulated comet model-making. The latest is an icy-glue construction of sorts. See the accompanying figure and the accurate but not-particularlyenlightening caption.

(Gombosi, Tamas I., and Houpis, Harry L.F.; "An Icy-Glue Model of Cometary Nuclei," Nature, 324:43, 1986.)

Reference. Cometary outbursts are cataloged in ACO20 on The Sun and Solar System Debris. For information on this book, visit: here.

Section through the icy-glue model of cometary nucleus. A section through the icy-glue model of cometary nucleus, showing active and inactive micropores, small boulders, and the outer dust covering.

From Science Frontiers #49, JAN-FEB 1987. 1987-2000 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