The diminutive size of cometary bodies is in no way proportional to their scientific importance. Theorists suggest that comets played a major role in the development of the Earth and subsequent collosions of comets may have wiped out various life forms, allowing only the most adaptable to develop further. In short, the study of comets is important from a historical perspective, scientifically compelling and, at the same time, entertaining. In this authoritative book, the development of cometary ideas is traced from antiquity through the actual fly-by of Halley by international spacecraft in 1986. The focus is on the cometary theories that were evident in each era. Included are many colorful anecdotes and information about culture and important personalities throughout history. Also contains an exhaustive catalog of all comet apparitions through the year 1700.

Reprint of the original, first published in 1871. The publishing house Anatiposi publishes historical books as reprints. Due to their age, these books may have missing pages or inferior quality. Our aim is to preserve these books and make them available to the public so that they do not get lost.

Comets have inspired wonder, excitement and even fear ever since they were first observed. But they are important members of the solar system, that contain material from early in the life of the system, held in deep-freeze. This makes them key in our understanding of the formation and evolution of many Solar System bodies. Recent ground- and space-based observations have changed much in our understanding of comets. Comets, and How to Observe Them gives a summary of our current knowledge and describes how amateur astronomers can contribute to the body of scientific knowledge of comets. This book contains many practical examples of how to construct comet light-curves, measure how fast a comet’s coma expands, and determine the rotation period of the nucleus. All these examples are illustrated with drawings and photographs. Because of their unpredictable nature comets are always interesting and sometime spectacular objects to observe and image. The second part of the book therefore takes the reader through the key observing techniques that can be used with commercially available modern observing equipment, from basic observations to more scientific measurements.

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.