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No. 91: Jan-Feb 1994

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Pairs Of Ghostly Spots Sweep Across Jupiter

Atop Hawaii's Mauna Kea, NASA's Infra-red Telescope Facility has detected a pair of infrared-bright spots that race across Jupiter's upper atmosphere in tune with the motion of Io, one of Jupiter's large, Galilean satellites. This synchronism suggests some sort of energy interchange between Io and the top of Jupiter's atmosphere. The theory now in vogue states that Jupiter's rotating magnetic field induces a voltage across 2300-mile-diameter Io, resulting in an electrical current of some 5 million amperes flowing between Io and Jupiter, some 262,000 miles away. In this bizarre electrical circuit, the two moving "terminals" on Jupiter, in the northern and southern hemispheres, are heated by the current flow and show up as fuzzy infrared-bright spots.

(Cowen, R.; "Jupiter and Io: Infrared Spots Mark Link," Science News, 144: 325, 1993.)

Comment. In passing, it should be remarked that Io is mantled by a cloud of electrically conducting sodium vapor. A weird moon in other respects, too, Io occasionally casts double shadows on Jupiter's upper atmosphere during transits. See AJX4 in The Moon and the Planets. In addition, in AJX2, infrared-hot shadows of the satellites Ganymede and Europa are mentioned. Very strange!

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From Science Frontiers #91, JAN-FEB 1994. 1994-2000 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