Home Truths Around Jupiter of Arizona Press)

75 N._::_:ATIJ=RE'--'-VO=L=.305"--'I'-=SEP1E:::....:..:::MBE-==R--'-'198-'-'-3------BOOK REVIEWS------------~ published earlier this year by the University Home truths around Jupiter of Arizona Press). The book ends with three appendices, a C.T. Russell single list of references and an index. The first is a list of symbols and acronyms Physics of the Jovian Magnetosphere. which was very handy in reading the book. Edited by A.J. Dessler. The second, especially welcome, discusses Cambridge University Press: 1983. coordinate systems; Dessler's jovial Pp.540. £25, $29.50. disposition is apparent in this attempt to prevent Jovian mispositions. The third appendix lists selected physical parameters EARLY in the era of space exploration we often find in conference proceedings. of Jupiter and Io. Finally, there is the sent probes to the planets simply to dis These papers have been carefully reviewed index, essential for any book of this type cover what was there. Later, as the glamour and the contributors, perhaps with the but all too often forgotten. of space exploration faded somewhat, it editor's encouragement, have responded In short this is nola run-of-the-mill con became fashionable (or perhaps necessary) well. As a result the book is safe for first ference proceedings' volume, but a to rationalize our quest to understand the year graduate students and others uniniti valuable thorough account of what we planets in terms of improving our under ated to the sometimes intense rivalries that know-and don't know- about Jupiter's standing of the Earth. have developed as resources for such magnetosphere. 0 But how can you learn anything about research have declined. The book would, the terrestrial magnetosphere from however, have benefited from a discussion Jupiter? The Jovian magnetosphere has of satellite atmospheres and ionospheres C. T. Russell is Professor of Geophysics and volcanoes in it, spewing out sulphur which (such a review is to be found in The Satel Space Physics at the University of California, becomes ionized and spun up by the rapid lites of Jupiter, edited by D. Morrison and Los Angeles. rotation of the planet. This rapidly rotating plasma stretches the Jovian field so that the magnetosphere is more disc-like than reader should also consult the special spherical. By contrast centrifugal force in Venusian probes Venus issues of the journal Icarus dated the terrestrial plasma has an insignificant August and November 1982. effect on the position of the magnetopause. Lionel Wilson A few of the papers in this volume are Jupiter emits powerful radio waves, too, devoted to useful historical summaries; the and releases energetic electrons which in Venus. rest are divided 14:6:5 among the at some energy ranges dominate solar elec Edited by D.M. Hunten, L. Colin, T.M. mosphere, ionosphere and surface, respec trons at the Earth many AU away. In Donahue and V.I. Moroz. tively. This emphasizes the leading role that addition to this, it has radiation belts which University of Arizona Press: 1983. studies of the atmosphere have played so Pp.l,l43. $49.95. roast our spacecraft if they linger too close far in the investigation of the evolution of to the planet. Venus, and underlines the great amount of We do learn of course. We learn basic CONSIDERING its similarity in size to the work remaining to be done on the chemical plasma physics; we gain insight into how Earth and its obvious importance in under and physical structure of the lithosphere, astrophysical plasmas may behave; we gain standing the origin and evolution of the the thermal state of the interior, and the an appreciation of processes which operate silicate planets, it is particularly unfor nature of the tectonic regimes that repre on less grand scales in the terrestrial mag tunate that Venus is so well equipped (by its sent the interaction between these two sys netosphere. And there are some processes opaque, dense, hot atmosphere) to hide its tems. Such studies are progressing steadily that operate almost identically on the two surface from our probes. However, tech as a synthesis takes place between the sur planets, such as ELF and VLF emissions. nological persistence pays off. To date, a face chemical analyses made by the soft On Earth, we cannot easily determine how total of thirteen Soviet and five American landers Veneras 13 and 14 and the radar much man's activity on the surface of the missions have visited Venus; the combined topography, roughness and dielectric cons planet affects the generation of these emis efforts have resulted in fifteen surface tant data obtained by the Pioneer Venus sions. The observations of Jupiter made so landers (some soft, some hard), seven fly Orbiter and by Earth-based radar measure far indicate that these waves do, in fact, bys and three orbiters which has led to a ments. However, one feels that it will be originate spontaneously in the plasma. steady increase in our knowledge of the some time before our understanding of the There is, however, still much to be planet. surface and interior matches that of the at learned, both from Jupiter and about it. A conference held in California in mosphere. Indeed the very structure of The Physics of November 1981 provided the opportunity With the inclusion of a paper summariz the Jovian Magnetosphere reflects the im for a detailed review of Venus studies (see ing the Venera 13 and 14 measurements, maturity of the discipline. There are eight Nature 296, 13-20; 1982), and this book made after the conference, this volume has observational papers centred around consists of much of the material presented the distinction of being a particularly up specific measurement techniques at the meeting together with numerous to-date representation of our knowledge of (magnetic fields, low energy particles, papers submitted later by Soviet authors. Venus. However, two more Soviet probes radio emissions, etc.) and four papers in As a result, the collection gives a well are even now en route to the planet, and the which theorists discuss their favourite balanced impression of the total effort be US Venus Radar Mapper probe is expected ideas. In a more mature phase of our ing directed at Venus. It is interesting that a to provide a very great increase in our understanding, such a book would have a number of the papers are co-authored by knowledge of the surface when it begins series of articles discussing physical Eastern-bloc and Western scientists, sym measurements in mid-1988. So with respect processes each of which covered all the bolic of an encouragingly high level of to the surface, we can assume that the best relevant observations and theories. But we scientific collaboration. So great has been is yetto come. 0 won't reach that stage for quite some time. the upsurge of interest in Venus, par In the meantime this book will have to ticularly since the arrival in orbit of the US suffice. The authors have written sound, Pioneer Venus Orbiter in 1978, that the Lionel Wilson is Head of the Planetary Sciences complete articles, not just the extended conference volume could not find room for Section of the Department of Environmental versions of oral presentations that you all of the papers submitted- the interested Sciences at Lancaster University. © 1983 Nature Publishing Group.

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