Number 10, November 27, 1990 by Phillip F. Schewe and Ben Stein A SODIUM NEBULA AROUND JUPITER may be the largest object in the solar system ever recorded on film. A group of astronomers at Boston University, working at the McDonald Observatory in Texas, have detected a neutral cloud of sodium out to distances beyond 400 Jovian radii. The Boston astronomers believe that the shape of the nebula will provide information about Jupiter's magnetosphere and that their technique of measuring non-spherical neutral clouds may be applicable to the study of other planetary magnetospheres. (Nature, November 22, 1990.) AFTER 75 YEARS GENERAL RELATIVITY is still alive and well. Clifford M. Will of Washington University (314-889-6244) reviews the many experimental tests of Albert Einstein's theory, from early measurements of the advance of Mercury's perihelion and the Sun's deflection of starlight, to today's observations of binary pulsars and the search for gravity waves, and finds "GR" to be as valid as ever. (Science, November 9, 1990.) EXTREMELY LIGHT AEROGELS, sometimes called "solid smoke," can support objects 1600 times their own weight. Lawrence W. Hrubesh (415-423-1691) and other scientists at the Lawrence Livermore National Lab have prepared aerogels with densities ranging from three up to 700 times that of air. Made from silica (or in some cases from organic compounds), these materials have extremely porous interiors and may therefore be useful as thermal insulators or as a host for catalysts. (Science News, November 17, 1990.) SATURN'S GREAT WHITE SPOT continues to grow. Hubble Space Telescope pictures show that the spot, observed first by ground-based telescopes in September, is now about 6000 miles wide and whirls eastward at about 1000 mph. NASA plans to convert its data into a short film to show how this "storm of the century" on Saturn has evolved. (The Washington Post, November 21, 1990.) SOLID STATE MICROBATTERIES ,now in development, may help facilitate three-dimensional high-density integrated circuit technology by providing power to components locally rather than from a remote source, thus reducing "crosstalk" between circuits. The new microbatteries, fabricated by laying down thin films with molecular beams, will be only 5 microns thick. (Physics World, November 1990.) A COLD FUSION CONFERENCE AT BRIGHAM YOUNG University last month provided no new support for room-temperature nuclear fusion. However, a few scientists, including the meeting organizer, Steven E. Jones (801-878-2749), continue to observe a low-level neutron production which, they insist, cannot be attributed to background sources. (Science, November 9, 1990.)