ICARUS 65, 1 5 9 - 1 6 0 (1986)
EDITORIAL The Jovian Atmospheres The eight flybys of the giant planets by the Pioneer and Voyager spacecraft have provided a staggering amount of information about the composition, meteorology, and structure of the Jovian atmospheres. During the past dozen years, clever models have been developed to interpret these spacecraft observations. Nevertheless very fundamental questions remain as to the dominant processes in these massive atmospheres. As with all components of the Solar System, the Jovian planets provide an opportunity to understand processes active elsewhere. Being intermediate in scale between stars and the gaseous envelopes of the terrestrial planets, the Jovian atmospheres may instruct the astronomical community about each. For example, like stars, Jupiter and Saturn presumably have unimportant boundary layer effects, because their solid cores are buried so deep, and hence one might anticipate that atmospheric motions of the giant planets will prove simpler than for the Earth's atmosphere. The equatorial jets, the symmetric belt/zone structure, and various elaborate atmospheric forms observed on Jupiter belie this hope. Similarly, with constituents other than water playing a putatively crucial part in determining atmospheric structure and dynamics, one might expect to elucidate the role played by condensation for Jupiter and Saturn. While this may still turn out to be true, it is yet to be obtained. Finally, since the giant planets are thought to have sampled fully the primordial solar nebula and to still retain it, their extant composition may indicate accurately the nebula's original makeup; unfortunately the present evidence as to the precise composition of the outer planets is unclear on this important matter. The keys to all these questions are better observations, improved data analysis, and wiser theories. The current issue o f h ' a r u s contains both review papers and contributed papers about the atmospheres of the Jovian planets. It shows that enormous progress has been made in understanding these complex systems but points out that synoptic studies and detailed in situ analysis, such as will be possible from the Galileo Orbiter and Probe, will be essential before a true understanding can be achieved. Almost all of these papers originated at a meeting held on May 6-8, 1985, at the Goddard Institute for Space Studies. The conference attracted more than 100 participants and was sponsored by NASA, Columbia University, and the Division for Planetary Sciences of the American Astronomical Society. The Conference was organized by M. D. Allison (Chairman), R. F. Beebe, M. J. S. Belton, B. J. Conrath, P. J. Gierasch, T. C. Owen, and R. A. West. A NASA Conference Publication, edited by L. D. Travis and M. D. Allison and also based on this meeting, is scheduled to appear late this spring; it contains the 30 or so contributed papers that are not being published in this special issue or another medium, abstracts of all presentations, and a transcript of the meeting's discussion. 159 0019-1035/86 $3.00 Copyright © 1986 by Academic Press, Inc. All rights of reproduction in any form reserved.
EDITORIAL I thank Michael Allison, Peter Gierasch, and the referees for help in putting this excellent issue together. Support from the National Aeronautics and Space Administration is also gratefully acknowledged. JOSEPH A. BURNS Space Sciences Building., ('ornell Uniw'r,~itv Ithaca. N e w York 14853