The IAU Symposium No. 62, 'The Stability of the Solar System and of Small Stellar Systems' was held in Warsaw in Poland during the Extraordinary General Assembly of the IAU in commemoration of the SOOth anniversary of the birth of Nicolaus Copernicus. The Symposium was sponsored by Commission 7 (Celestial Mechanics) and cosponsored by Commissions 4 (Ephemerides) and 37 (Star Clusters and Asso- ciations) of the IAU and by IUTAM. The Organizing Committee included Y. Kozai (Chairman), J. A. Agekjan, A. Deprit, G. N. Duboshin, S. G\lska (Local represen- tative), M. Henon, B. Morando and C. Parkes (IUTAM representative). The Symposium was supported financially by the IA U, the IUT AM and the Polish Academy of Sciences. Y. KOZAI Chairman of the Organizing Committee STABILITY THEORY IN CELESTIAL MECHANICS J MOSER Courant Institute of Mathematical ScIences, New York University, New York, N. Y. 10012, U.S.A. Abstract, This expository lecture surveys recent progress of the stability theory in Celestial Mechanics with emphasis on the analytical problems. In particular, the old question of convergence of perturbation series are discussed and positive results obtained, in the light of the work by Kolmogorov Arnold and Moser. For the three body problem, classes of quasi-periodic solutions and doubly asymptotic (or homo- clinic) orbits are discussed.

Over the past two decades auroral science has developed from a somewhat mysterious and imprecise specialty into a discipline central in the study of the ionosphere and magnetosphere. The investigation of aurora unites scientists with very different backgrounds and interests so that it is difficult to write a self-contained account of the field in a book of reasonable length. In this work I have attempted to include those aspects of theory which I have found valuable in predicting the effects on the atmosphere of auroral particle precipitation. In addition I have attempted to describe the techniques of observation with particular emphasis on optical methods which have been useful. While the aeronomy of aurora has been regarded as central, the mechanisms by which particles are accelerated and precipitated into the atmosphere is of no less interest. This aspect of the subject has however been treated in a briefer fashion since it is a part of the immense and rapidly developing field of magnetospheric science. Generally I have attempted to provide a coherent introduction to auroral science with an emphasis on relatively simple physical interpretations and models. References are given to enable the reader to find more extensive or rigorous discussions of particular topics. A fairly complete, quantitative atlas of the auroral spectrum is included.

It was about fourteen years ago that some of us became intrigued with the idea of searching the sky for X-ray and gamma-ray sources other than the Sun, the only celestial emitter of high-energy photons known at that time. It was, of course, clear that an effort in this direction would not have been successful unless there occurred, somewhere in space, processes capable of producing high-energy photons much more efficiently than the processes responsible for the radiative emission of the Sun or of ordinary stars. The possible existence of such processes became the subject of much study and discussion. As an important part of this activity, I wish to recall a one-day conference on X-ray astronomy held at the Smithsonian Astrophysical Observatory in 1960. The theoretical predictions did not provide much encouragement. While several 'unusual' celestial objects were pin-pointed as possible, or even likely, sources of X-rays, it did not look as if any of them would be strong enough to be observable with instru mentation not too far beyond the state of the art. Fortunately, we did not allow our selves to be dissuaded. As far as I am personally concerned, I must admit that my main motivation for pressing forward was a deep-seated faith in the boundless re sourcefulness of nature, which so often leaves the most daring imagination of man far behind."

The aim of the present book will be to summarize the results of the space exploration of the Moon in the past fifteen years -culminating in the manned Apollo missions of 1969-1972 -on the background of our previous acquaintance with our satellite made in the past by astronomical observations at a distance. Astronomy is one of the oldest branches of science conceived by the inquisitive human mind; though until quite recently it had been debarred from the status of a genuine experimental science by the remoteness of the objects of its study. With the sole exception of meteoritic matter which occasionally finds its way into our labora tories, all celestial bodies could be investigated only at a distance: namely, from the effects of attraction exerted by their mass, or from the ciphered messages of their light carried by nimble-footed photons across the intervening gaps of space. A dramatic emergence oflong-range spacecraft -capable of carrying men with their instruments not only outside the confines of our atmosphere, but to the actual surface of our nearest celestial neighbour - has since 1957 thoroughly changed this time honoured picture. In particular (as we shall detail in Chapter 1 of this book) space astronomy ofthe Moon is barely 15 years old. But relative infant as it is by age, it has already provided us with such a tremendous amount of new and previously inacces sible scientific data as to virtually revolutionalize our subject."

The devotion of an IA U symposium entirely to the topic of chromo spheric fine structure at a time when models of the spherically symmetric chromosphere are still evolving constitutes a valid recognition of the growing feeling among solar astron omers that the chromosphere cannot be understood independently of its discrete structural features. Network structure, which seemingly borders the photospheric supergranule cells, persists intact throughout the chromosphere and most of the chromosphere-corona transition region. The network is the locus of the bright coarse mottles, and the spicule bushes and is the terminus for one end of the quiet chromo spheric fibrils as well. Additionally, it is the locus of most of the magnetic flux of the quiet chromosphere. It is not surprising, therefore, that current studies of the chromosphere tend to center around efforts to better describe the network phenom ena and to ascertain the physical properties of the network features. Clearly, the supergranule cells and associated network structures constitute a fundamental and singularly important feature of solar structure in the boundary layers. Just as it is now clear that much of the chromo spheric fine structure is associated with the network bordering supergranule cells, it seems equally clear that structural features are almost universally associated with both fluid flow and magnetic geometry. Indeed, many observers claim that the brightness features faithfully map the mag netic lines offorce while still others claim that associated with each class of brightness feature there is a more or less unique fluid flow."

o beaute sans seconde SeuIe sembIabIe Ii toi SOLEIL pour tout Ie monde ... JEAN-FRANc;OIS SARASIN (1615-1654) The last decade has seen the publication of monographs covering most areas of solar activity: flares (Smith and Smith, 1963), sunspots (Bray and Loughhead, 1964) and the corona (Billings, 1966). Consequently, of all the major manifestations of solar activity only prominences are without a comprehensive and unified treatment in the current literature. The present book is written in an attempt to remedy this situation, and to furnish an account of some of the most spectacular and most beautiful aspects of solar activity. Our ultimate aim is an understanding of the physical processes involved. I hope that this book may provide if only a small step toward this goal. After an historical introduction and some general definitions Chapter I proceeds with an account of several classification schemes for prominences. Most of the observational material is presented in Chapter II and forms the basis on which different models of prominences are built in Chapter III. Chapters IV and V give most of the physics of prominences, treating, as they do, the formation and stability of these objects. The interaction of prominences with other manifestations of solar activity is the subject of Chapter VI, and the final Chapter VII considers prominences in the larger context: as an integral part of the corona.

Discover the mysteries of the Universe and journey to galaxies beyond our own in this fact-packed companion to space. From icy worlds and hot, fiery giants to the biggest telescopes and latest spacecraft, this book covers more than 40 profiles of the planets, stars, and objects in our universe. Find out all about our neighboring planets, from tiny Mercury to gigantic Jupiter. Discover what lies beyond our solar system and the stars we can see in the night sky. Learn about the latest space technology and when humans may finally land on Mars. Broken down by type, each object is presented in a clear, engaging way, with stunning images and bite-sized chunks of information. Detailed NASA photography brings the mysteries of outer space to life, while pronunciation guides help with tricky names, and a visual index gives a quick overview of all the key objects in the book. Filled with fascinating details for every young stargazer and budding astronaut, My Book of Stars and Planets is the perfect first reference book on space and the universe for kids.

This book provides readers with an understanding of the basic physics and mathematics that governs our solar system. It explores the mechanics of our Sun and planets; their orbits, tides, eclipses and many other fascinating phenomena. This book is a valuable resource for undergraduate students studying astronomy and should be used in conjunction with other introductory astronomy textbooks in the field to provide additional learning opportunities. Features: Written in an engaging and approachable manner, with fully explained mathematics and physics concepts Suitable as a companion to all introductory astronomy textbooks Accessible to a general audience

Meteorites are fascinating cosmic visitors. Using accessible language, this book documents the history of mineralogy and meteorite research, summarizes the mineralogical characteristics of the myriad varieties of meteorites, and explains the mineralogical characteristics of Solar System bodies visited by spacecraft. Some of these bodies contain minerals that do not occur naturally on Earth or in meteorites. The book explains how to recognize different phases under the microscope and in back-scattered electron images. It summarizes the major ways in which meteoritic minerals form - from condensation in the expanding atmospheres of dying stars to crystallization in deep-seated magmas, from flash-melting in the solar nebula to weathering in the terrestrial environment. Containing spectacular back-scattered electron images, colour photographs of meteorite minerals, and with an accompanying online list of meteorite minerals, this book provides a useful resource for meteorite researchers, terrestrial mineralogists, cosmochemists and planetary scientists, as well as graduate students in these fields

Illustrated with breathtaking images of the Solar System and of the Universe around it, this book explores how the discoveries within the Solar System and of exoplanets far beyond it come together to help us understand the habitability of Earth, and how these findings guide the search for exoplanets that could support life. The author highlights how, within two decades of the discovery of the first planets outside the Solar System in the 1990s, scientists concluded that planets are so common that most stars are orbited by them. The lives of exoplanets and their stars, as of our Solar System and its Sun, are inextricably interwoven. Stars are the seeds around which planets form, and they provide light and warmth for as long as they shine. At the end of their lives, stars expel massive amounts of newly forged elements into deep space, and that ejected material is incorporated into subsequent generations of planets. How do we learn about these distant worlds? What does the exploration of other planets tell us about Earth? Can we find out what the distant future may have in store for us? What do we know about exoworlds and starbirth, and where do migrating hot Jupiters, polluted white dwarfs, and free-roaming nomad planets fit in? And what does all that have to do with the habitability of Earth, the possibility of finding extraterrestrial life, and the operation of the globe-spanning network of the sciences?

This book provides readers with an understanding of the basic physics and mathematics that governs our solar system. It explores the mechanics of our Sun and planets; their orbits, tides, eclipses and many other fascinating phenomena. This book is a valuable resource for undergraduate students studying astronomy and should be used in conjunction with other introductory astronomy textbooks in the field to provide additional learning opportunities. Features: Written in an engaging and approachable manner, with fully explained mathematics and physics concepts Suitable as a companion to all introductory astronomy textbooks Accessible to a general audience

Many astrophysical bodies produce winds, jets or explosions, which blow spectacular bubbles. From a nonmathematical, unifying perspective, based on the understanding of bubbles, the authors address many of the most exciting topics in modern astrophysics including supernovae, the production of structure in the Early Universe, the environments of supermassive black holes and gamma-ray bursts.

Every rock has a story tell, and none more so than those which have fallen from the sky: meteorites. Originating in the Asteroid Belt between Mars and Jupiter, these rocky fragments offer clues not just to the earliest origins of the Solar System but also to Earth's very survival into the future. Sky at Night presenter, Dr Tim Gregory takes us on a journey through the very earliest days of our Solar System to the spectacular meteorite falls that produced 'fiery rain' in 1792, to the pre-solar grains (literally stardust) that were blown in from other solar systems and are the oldest solid objects ever discovered on earth. Meteorites reveal a story much bigger than ourselves or our planet. As Tim says, 'it is an epic beyond compare'.

This book introduces the reader to all the basic physical building blocks of climate needed to understand the present and past climate of Earth, the climates of Solar System planets, and the climates of extrasolar planets. These building blocks include thermodynamics, infrared radiative transfer, scattering, surface heat transfer and various processes governing the evolution of atmospheric composition. Nearly four hundred problems are supplied to help consolidate the reader's understanding, and to lead the reader towards original research on planetary climate. This textbook is invaluable for advanced undergraduate or beginning graduate students in atmospheric science, Earth and planetary science, astrobiology, and physics. It also provides a superb reference text for researchers in these subjects, and is very suitable for academic researchers trained in physics or chemistry who wish to rapidly gain enough background to participate in the excitement of the new research opportunities opening in planetary climate.

Copernicus sowed the seed from which science has grown to be a dominant aspect of modern culture, fundamental in shaping our understanding of the workings of the cosmos. John Henry reveals why Copernicus was led to such a seemingly outrageous and implausible idea as a swiftly moving Earth.

How do planetary scientists analyze and interpret data from laboratory, telescopic, and spacecraft observations of planetary surfaces? What elements, minerals, and volatiles are found on the surfaces of our Solar System's planets, moons, asteroids, and comets? This comprehensive volume answers these topical questions by providing an overview of the theory and techniques of remote compositional analysis of planetary surfaces. Bringing together eminent researchers in Solar System exploration, it describes state-of-the-art results from spectroscopic, mineralogical, and geochemical techniques used to analyze the surfaces of planets, moons, and small bodies. The book introduces the methodology and theoretical background of each technique, and presents the latest advances in space exploration, telescopic and laboratory instrumentation, and major new work in theoretical studies. This engaging volume provides a comprehensive reference on planetary surface composition and mineralogy for advanced students, researchers, and professional scientists.

"Have you ever seen a total solar eclipse?" If the question caused you to search your memory, the correct answer would have been "no." A common response is: "Yes-I saw one, it was about 90% partial eclipse where I lived." A 90% partial eclipse is indeed a remarkable phenomenon, but true totality leaves all else in the shade, in all senses of the phrase. Ask the question of anyone who has experienced the full sensation of being obliterated by the moon's shadow, and they will reply "yes"-without hesitation-and continue with a monologue describing the overwhelming experiences and unique phenomena that ensued. On 21 August 2017 millions of people across the United States witnessed "The Great American Eclipse" of the Sun. The moment it was over, people around the world were asking questions: what caused the weird shadows and colors in the build up to totality? Were those ephemeral bands of shadows gliding across the ground in the seconds before totality real or an optical illusion? Why this, what that, but above all: where and when can I see a total solar eclipse again? Eclipses: What Everyone Needs to Know helps explain the profound differences between a 99.99% partial eclipse and true totality, and inform readers how to experience this most beautiful natural phenomenon successfully. It covers eclipses of sun, moon, and other astronomical objects, and their applications in science, as well as their role in history, literature, and myth. It describes the phenomena to expect at a solar eclipse and the best ways to record them-by camera, video, or by simple handmade experiments. The book covers the timetable of upcoming eclipses, where the best locations will be to see them, and the opportunities for using them as vehicles for inspiration and education. As a veteran of seven total solar eclipses, physicist Frank Close is an expert both on the theory and practice of eclipses. Eclipses: What Everyone Needs to Know is a popular source of information on the physics of eclipses.