In May 1998 a hundred renowned scientists from 20 different countries met at the Max-Planck-Institut für Aeronomie to communicate their latest results and ideas in astrophysical and space plasma, as a follow-up to previous similar meetings which were held in Varenna, Abastumai, Potsdam, Toki and Guaruja. The main papers emerging from this meeting are collected in this volume. They deal with fundamental plasma phenomena, particle and radiation processes in astrophysics and space physics as the origin of magnetic activity, the basic mechanisms of particle acceleration and plasma heating common to plasma in galaxies and at the sun as well as in planetary magnetospheres. New observational results from YOHKOH, SOHO and other missions are presented. Using these, the basic physical processes leading to coronal heating and solar/stellar wind acceleration are discussed. Other topics are the microphysics of shock waves and transport phenomena in collisionless plasmas and the physics of thin plasma boundaries. The volume also treats the ionic composition of plasma and dust in the Universe and their observability in the solar system. A CD-ROM is attached which adds a valuable multimedia component, illuminating results of observations, theory and simulations. Everyone interested in astrophysical plasmas, its radiation and charged particle aspects, and advanced or even beginning students will find references to nearly all modern aspects of plasma astrophysics and space physics as well as an overview of current research results.

As this excellent book demonstrates, the study of comets has now reached the fas cinating stage where we understand comets in general simple tenns while, at the same time, we are uncertain about practically all the details of cometary nature, structure, processes, and origin. In every aspect, even including dynamics, a choice among several or many competing theories is made impossible simply by the lack of detailed knowledge. The space missions, snapshot studies of two comets, partic ularly the one that immortalizes the name of Sir Edmund Halley, have produced a huge mass of valuable new infonnation and a number of surprises. Nonetheless, we face the tantalizing realization that we have obtained only a fleeting glance at two of perhaps a hundred billion (lOll) or more comets with possibly differing natures, origins, and physical histories. To my personal satisfaction, comets seem to have discrete nuclei made up of dirty snowballs, as I concluded four decades ago, but perhaps they are more like frozen rubbish piles.

Dissociative Recombination of Molecular Ions with Electrons is a comprehensive collection of refereed papers describing the latest developments in dissociative recombination research. The papers are written by the leading researchers in the field. The topics covered include the use of microwave afterglows, merged beams and storage rings to measure rate coefficients and to identify the products and their yields. The molecules studied range in size from the smallest, H2+, to bovine insulin ions. The theoretical papers cover the important role of Rydberg states and the use of wave packets and quantum defect theory to deduce cross sections, rate constants and quantum yields. Several theoretical and experimental papers address the controversial topic of H3+ dissociative recombination and its importance in the interstellar medium. Dissociative recombination studies of other molecular ions in the interstellar medium and in cometary and planetary atmospheres are covered. Ionization is an important competitive process to dissociative recombination and its competition with predissociation and its role in the reverse process of the association of neutral species is presented. Dissociative attachment, in which an electron attaches to a neutral molecule, has many similarities to dissociative recombination. The topics covered include the accurate calculation of electron affinities, attachment to molecules, clusters, and to species absorbed on solid surfaces and electron scattering by a molecular anion.