This revised edition places a unique emphasis on all the new results from ground-based, satellites and space missions — detection of molecule H2 and prompt emission lines of OH for the first time; discovery of X-rays in comets; observed diversity in chemical composition among comets; the puzzle of the constancy of spin temperature; the well-established mineralogy of cometary dust; extensive theoretical modeling carried out for understanding the observed effects; the similarity in the mineralogy of dust in circumstellar shell of stars, comets, meteorites, asteroids and IDPs, thus indicating the generic relationship between them.

The study of Comet Halley in 1986 was a tremendous success for cometary science. In March of that year, six spacecrafts passed through Comet Halley as close as 600 km from the nucleus and made the in situ measurements of various kinds. These space missions to Comet Halley and that of the ICE spacecraft to Comet Giacobini-Zinner combined with studies, both ground-based and above the atmosphere, have increased our knowledge of cometary science in a dramatic way.This new edition of Physics of Comets incorporates these new and exciting findings. The emphasis of the book is on the physical processes operating in a cometary environment. It discusses up-to-date observations, methods and results based on the study of various comets. The subject is developed in a systematic manner covering various aspects of cometary phenomena. This book may serve as a text book for students, and as reference material for researchers.

This revised edition places a unique emphasis on all the new results from ground-based, satellites and space missions ? detection of molecule H2 and prompt emission lines of OH for the first time; discovery of X-rays in comets; observed diversity in chemical composition among comets; the puzzle of the constancy of spin temperature; the well-established mineralogy of cometary dust; extensive theoretical modeling carried out for understanding the observed effects; the similarity in the mineralogy of dust in circumstellar shell of stars, comets, meteorites, asteroids and IDPs, thus indicating the generic relationship between them.

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.

This book provides a comprehensive overview of our current knowledge of comets. It presents a fascinating survey of the study of comets throughout history, from antiquity to the present day, and includes the most recent discoveries on the exceptional comets Hale-Bopp and Hyakutake. The authors discuss the role of comets in the formation of our Solar System and describe the links between comets, asteroids and the recently discovered Kuiper-belt objects. The book also includes new insights into the composition and nature of cometary nuclei, with results from the most up-to-date observation techniques. Written in a clear and lively style, and beautifully illustrated, this book will appeal to anyone interested in comets and astronomy, professionals and amateurs alike. It will be of particular interest to students and researchers in astronomy, astrophysics and planetary science, as well as general readers with a good background in physics.

Written by a leading expert on comets, this textbook is divided into seven main elements with a view to allowing advanced students to appreciate the interconnections between the different elements. The author opens with a brief introductory segment on the motivation for studying comets and the overall scope of the book. The first chapter describes fundamental aspects most usually addressed by ground-based observation. The author then looks at the basic physical phenomena in four separate chapters addressing the nucleus, the emitted gas, the emitted dust, and the solar wind interaction. Each chapter introduces the basic physics and chemistry but then new specific measurements by Rosetta instruments at comet Churyumov-Gerasimenko are brought in. A concerted effort has been made to distinguish between established fact and conjecture. Deviations and inconsistencies are brought out and their significance explained. Links to previous observations of comets Tempel 1, Wild 2, Hartley 2, Halley and others are made. The author then closes with three smaller chapters on related objects, the loss of comets, and prospects for future exploration. This textbook includes over 275 graphics and figures – most of which are original. Thorough explanations and derivations are included throughout the chapters. The text is therefore designed to support MSc. students and new PhD students in the field wanting to gain a solid overview of the state-of-the-art.