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No. 20: Mar-Apr 1982

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Something hot beneath small saturn-satellite surfaces

Crater-density studies of the small, icy Saturn satellites Rhea, Dione, Mimas, and Tethys reveal important non-uniformities in crater distribution and age. The anomalies are so large that astronomers have concluded that these objects must have undergone considerable evolution after they were formed by accretion (the currently accepted mode of formation). Unfortunately these four satellites are so small that they could not have accommodated any reasonable energy source capable of causing the observed crustal evolution. The authors suggest strong local concentrations of radioactive heat generators rather than uniformly distributed radiogenic substances, such as those that helped mould the earth's surface.

(Plescia, J.B., and Boyce, J.M.; "Crater Densities and Geological Histories of Rhea, Dione, Mimas and Tethys," Nature, 295:285, 1982.)

Comment. Interestingly enough, local concentrations of radioactivity have been discovered on the moon.

From Science Frontiers #20, MAR-APR 1982. 1982-2000 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