The cover picture of this volume displays one of the most advanced products of he lioseismic research: a view into the deep interior of the sun, revealing its distinctly non-uniform rotation throughout the entire depth of the convection zone. Just over 20 years ago, the first successful helioseismic experiment disclosed an increase of ro tation velocity in the uppermost one dozen megameters below the photosphere. The stunning progress in depth and detail highlighted by the cover diagram (and by others shown in this volume as well) was made possible by considerable advances in instru mentation, by the development of powerful analytical tools and, foremost, by the involvement of new brains of enthusiastic proselytes and newcomers to the field, in creasing nearly exponentially in number every year. New branches of research widened the scope of "uranoseismology", as e. g. time-distance seismology (the promising av enue towards small-scale and short-time variability), atmospheric seismology (a new look at strange phenomena we have all ways seen, but hardly understood), and finally the growing observational assault on hundreds of individual stars which are either manifestly or supposedly oscillating -i. e. asteroseismology. The formation of numer ous solar and stellar observing networks and, ultimately, space missions like SOHO have greatly promoted the potential of this science. This steady progress was accompanied by workshops, colloquia, and symposia in quick succession.

Transient phenomena are short-lived astronomical events, unusual in a science in which time is more often measured in millennia than milliseconds. There is a fascination with transient phenomena, predictable or otherwise, that astronomers of all abilities share. In Meteors, Comets, Supernovae, Neil Bone gives guidelines for observers, including the best possible periods (months or years) to see seasonal but unpredictable phenomena like meteors and sunspots. Recording such outbursts involves visual observing techniques, photography, and even the relatively new field of the video recording of meteors, which are also examined in detail. The book also includes material about phenomena that occur in the lower atmosphere (such as "ozone eaters", nacreous clouds, solar and lunar haloes), which although not strictly astronomical in their nature attract the attention of dedicated sky-watchers.

In 1961, President John F. Kennedy issued a challenge: the United States would land a man on the moon and return him safely to Earth before the end of the decade. It seemed like an impossible task and one that the Russians--who had launched the first satellite and put the first man into Earth orbit--would surely perform before us. The ingenuity, passion, and sacrifice of thousands of ordinary men and women, from all walks of life, enabled the space program to meet this extraordinary goal. In all, six crews would land on the moon before Congress withdrew financial backing for the program. This is the story of those men and women who worked behind the scenes, without fanfare or recognition, to make these missions a success. Thirty years later, they still speak of Apollo with pride, sometimes even awe. After Apollo moonwalker John Young told journalist Billy Watkins in a 1999 interview that "nobody knows anything about the people who helped make those flights so successful," Watkins made it his mission to identify the unsung heroes and learn their stories. His subjects include: BLJulian Scheer (NASA publicist): Argued for and won the inclusion of a television camera on Apollo 11, enabling Armstrong's walk on the moon to be broadcast and recorded for posterity. BLSonny Morea, lead designer of the Lunar Rover. BLHugh Brown, one of the few African Americans who worked on the Apollo program, helped monitor for Russian submarines trying to jam NASA communication during launches, and later went on to become head of the Federal Reserve Bank in Atlanta. BLJoAnn Morgan, launch control: One of the few women involved in the space program, Morgan was designated the "lightning specialist." Herknowledge was crucial when the Apollo 12 spacecraft was struck by lightning only seconds after liftoff, nearly causing an abort. She was one of the few specialists allowed in the "firing room" during liftoff. BLJoan Roosa, widow of Apollo 14 astronaut Stuart Roosa, talks about the sacrifices of the families and their devotion to "The Program." BLJoe Schmitt, veteran suit technician was responsible for making sure the suits were leak-proof and hooked up correctly--knowing any mistake would mean instant death in space. BLJoseph Laitin, who came up with the idea for the Apollo 8 astronauts to read the first ten verses of Genesis during their Christmas Eve television broadcast from the moon. BLClancy Hatelberg, the Navy diver, who plucked the first humans to walk on the moon from the Pacific Ocean after the Apollo 11 landing.

In the past decade, indirect (Doppler) imaging techniques have opened up a whole new discipline in stellar astronomy, providing increasingly detailed photometric, magnetic, and chemical inhomogeneity images of stellar surfaces. Furthermore, new optical interferometers are already being used with sophisticated interferometer techniques to image stellar surface structures more directly, and in the future the ESO VLT Interferometer and other instruments will extend these capabilities enormously. These developments are highlighted in the first two sections of this book. The large number of recent results, ground-based and space-based, and the lack of a generally accepted dynamo theory with predictive power for the stars and the Sun, result in an ever-growing complexity of interpretation of individual results. The IAU Symposium 176 on Stellar Surface Structure' consequently focused on spatially resolved stellar observations throughout the H-R diagram, from O- and B-stars to late M-stars. Two further sections in this book summarize the current observational data on surface inhomogeneities in stellar photospheres, chromospheres, and coronae. Finally, a special section is devoted to next generation model atmospheres.

This book chronicles the history of climate science and planetary exploration, focusing on our ever-expanding knowledge of Earth's climate, and the parallel research underway on some of our nearest neighbours: Mars, Venus and Titan. From early telescopic observation of clouds and ice caps on planetary bodies in the seventeenth century, to the dawn of the space age and the first robotic planetary explorers, the book presents a comprehensive chronological overview of planetary climate research, right up to the dramatic recent developments in detecting and characterising exoplanets. Meanwhile, the book also documents the discoveries about our own climate on Earth, not only about how it works today, but also how profoundly different it has been in the past. Highly topical and written in an accessible and engaging narrative style, this book provides invaluable historical context for students, researchers, professional scientists, and those with a general interest in planetary climate research.

On July 16, 1994 a world-shattering event occurred that would rivet our attention for six explosive days and go on to make history as the single most important celestial event of the century. Comet Shoemaker-Levy 9 crashed into Jupiter, changing forever our understanding of comets and cosmic cataclysms. Our own sense of security would never be the same as the world witnessed fragment after fragment of the comet bash into Jupiter with the collective equivalent force of a 50-million-megaton bomb. David Levy, co-discoverer of periodic Comet Shoemaker-Levy 9, shares his once-in-several-lifetimes' story from the time of the discovery, with Eugene and Carolyn Shoemaker, of this unusual "squashed" comet to the later shocking revelation of hearing that "their" comet was destined to collide with Jupiter. Never in recorded history has a comet created such a catastrophic event as smashing into a planet. Impact Jupiter takes off where David Levy's earlier acclaimed book, The Quest for Comets, left us. Magnificent photos of the impacts, including superb color pictures, accompany David's poetic words, vividly bringing to life his thrilling story. Savor the words of one of the world's most celebrated amateur astronomers as he humbly and eloquently opens the beauty of the heavens to all who are curious.

Mars has always held a special interest because of the possibility that life may have existed there. The story of water on Mars is crucial for understanding the planet's geological, climatological, and biological history. In this book Dr. Carr summarizes the history of water on Mars. He highlights problems confronted, addressing them from the records of the morphology of the surface and the chemistry and mineralogy of some near-surface rocks, as revealed in meteorites originating on Mars. The book is well illustrated with imagery from the Viking missions. The water story has important implications for the future exploration of the planet.

A complete revision of Goody's classic 1964 work, this volume offers a systematic discussion of atmospheric radiation processes that today are at the center of worldwide study and concern. It deals with the ways in which incident solar radiation is transformed into scattered and thermal radiation, and the thermodynamic consequences for the Earth's gaseous envelope, identifying aspects of the interaction between radiation and atmospheric motions as the central theme for atmospheric radiation studies. As a complete treatment of physical and mathematical foundations, the text assumes no prior knowledge of atmospheric physics. The theoretical discussion is systematic, and can therefore be applied with minor extension to any planetary atmosphere.

It is a pleasure to present this work, which has been well received in Gennan-speaking countries through four editions, to the English-speaking reader. We feel that this is a unique publication in that it contains valuable material that cannot easily-if at all-be found elsewhere. We are grateful to the authors for reading through the English version of the text, and for responding promptly (for the most part) to our queries. Several authors have supplied us, on their own initiative or at our suggestion, with revised and updated manuscripts and with supplementary English references. We have striven to achieve a translation of H andbuch flir Sternfreunde which accurately presents the qualitative and quantitative scientific principles con tained within each chapter while maintaining the flavor of the original Ger man text. Where appropriate, we have inserted footnotes to clarify material which may have a different meaning and/or application in English-speaking countries from that in Gennany. When the first English edition of this work, Astronomy: A Handbook (translated by the late A. Beer), appeared in 1975, it contained 21 chapters. This new edition is over twice the length and contains 28 authored chap ters in three volumes. At Springer's request, we have devised a new title, Compendium of Practical Astronomy, to more accurately reflect the broad spectrum of topics and the vast body of infonnation contained within these pages.

THE MEETING The IAU Symposium 160 ASTEROIDS COMETS METEORS 1999 has been held at Villa Carlotta in Belgirate, on the shore of Lago Maggiore (Italy), from June 14 to June 18, 1993. It has been organized by the Astronomical Observatory of Torino and by the Lunar and Planetary Institute of Houston. It has been a very large meeting, with 323 registered participants from 38 countries. The scientific program included 29 invited reviews, 106 oral communications, and 215 posters. The subjects covered included all the aspects of the studies of the minor bodies of the solar system, including asteroids, comets, meteors, meteorites, interplanetary dust, with special focus on the interrelationships between these. The meeting was structured as follows. 5 morning plenary sessions have been devoted to invited reviews on: (1) search programs (2) populations of small bodies (3) dynamics (4) physical observations and modelling (5) origin and evolution. Two afternoon plenary sessions have been devoted to space missions to small bodies and to interrelationships between the different populations. The afternoon parallel sessions have been devoted to: dynamics of comets; Toutatis, Ida, Gaspra; physical processes in cometary comae and tails; meteorites; the cosmogonic message from cometary nuclei; physics of asteroids; the interplanetary dust complex; comet nuclei; meteors; composition and material properties of comets; dynamics of asteroids.

The brilliant trailing beauty of fiery comets has inspired fear, wonder, and awe since the dawn of human history. Brighter than stars, moving and disappearing in their own singular orbits, comets have been among the most mysterious elements in the sky, eluding our understanding until very recently. With the aid of space probes, scientists have discovered that these swiftly moving chunks of ice and carbon are more plentiful and far more dangerous than suspected. Scientists are also beginning to realize the monumental role played by comets in the development of the Earth and solar system. David Levy describes in dramatic detail the thrilling yet often devastating effects of comet collisions. In the dawn of our solar system, the Earth was barraged with comets that may have carried the materials necessary to lay the foundations for life on this planet. Levy also presents compelling evidence for later comet collisions, including those of the age of dinosaurs. Great impacts, Levy asserts, not only caused the extinction of the dinesaurs, but ushered in new species of life. As Levy so clearly explains, scientists are realizing that comet collisions are virtually inevitable. Levy reveals possible future collisions with the Earth and describes the terrible risks to life they would pose. He even shows how we might prepare to withstand the impact of large comets in the future.

Meteorites - as well as shooting stars and meteors - result from a collision of a solid body from space with our Earth, but only meteorites are able to penetrate the Earth's protective shield, the atmosphere, and fall to the Earth's surface. Apart from lunar samples, they are the only materials from beyond the Earth which we can probe and study.
This book gives a concise and up-to-date description of meteorites - fall phenomena, chemical and mineral composition, classification - as well as a discussion of their formation and origin, which also tells us the story of the formation of our planetary system. The text is understandable for laymen and students, but can also be used as an introduction to the field for students and scientists.

Infrared Solar Physics contains the proceedings of the 154th Symposium of the International Astronomical Union held in Tucson, Arizona, March 2--5, 1992. Aimed at active workers and graduate students in solar physics, this volume provides the first comprehensive view of a rapidly expanding discipline that gives us a new perspective on the sun. Measurements across the wide infrared spectral range -- here, from 1 mum to 1 mm -- can probe the solar atmosphere from below the visible surface through the outer reaches of the corona. Taking full advantage of revolutionary advances in detector technology, infrared observations from the ground, aircraft and space have led to a better understanding of solar magnetic fields, atmospheric structure and activity, and elemental abundances. The infrared has also provided new interpretive challenges, such as the appearance of the 12-mum emission lines of magnesium. These and other developments are discussed here by the leading contributors to the field, who also give their perspectives on the future of this rich field of study.

This introduction to planetary geology concentrates on the surface features of the planets and satellites of our Solar System. The author first discusses the primary processes that shape our planet, Earth, and the geomorphology of the objects in the Solar System. The second edition includes new information about Venus and a new chapter on Neptune. The book is beautifully illustrated with high-resolution black-and-white photographs from recent space probes and orbiting spacecraft, and with explanatory diagrams. Each chapter starts with a description of the general physiography and terrain units, then the geomorphic processes that created them are discussed. Finally a synopsis of the geologic evolution of the surface is given. The selected references at the end include original papers, review articles and books.

This symposium was devoted to a new celestial mechanics whose aim has become the study of such `objects' as the planetary system, planetary rings, the asteroidal belt, meteor swarms, satellite systems, comet families, the zodiacal cloud, the preplanetary nebula, etc. When the three-body problem is considered instead of individual orbits we are, now, looking for the topology of extended regions of its phase space. This Symposium was one step in the effort to close the ties between two scientific families: the observationally-oriented scientists and the theoretically-oriented scientists.

As in all other fields of astronomy, progress in instrumentation and observational techniques has in recent years brought a wealth of new information about the sun. This introduction presents a complete overview of solar physics, of what we know and would like to know. The increasing number of observations of solar pheno- mena on neighbouring stars makes this book valuable not only for students specializing in solar physics but also for researchers interested in stellar structure and the solar-stellar connection.

The birth and evolution of our solar system is a tantalizing mystery that may one day provide answers to the question of human origins. From Dust to Life tells the remarkable story of how the celestial objects that make up the solar system arose from common beginnings billions of years ago, and how scientists and philosophers have sought to unravel this mystery down through the centuries, piecing together the clues that enabled them to deduce the solar system's layout, its age, and the most likely way it formed. Drawing on the history of astronomy and the latest findings in astrophysics and the planetary sciences, John Chambers and Jacqueline Mitton offer the most up-to-date and authoritative treatment of the subject available. They examine how the evolving universe set the stage for the appearance of our Sun, and how the nebulous cloud of gas and dust that accompanied the young Sun eventually became the planets, comets, moons, and asteroids that exist today. They explore how each of the planets acquired its unique characteristics, why some are rocky and others gaseous, and why one planet in particular--our Earth--provided an almost perfect haven for the emergence of life. From Dust to Life is a must-read for anyone who desires to know more about how the solar system came to be. This enticing book takes readers to the very frontiers of modern research, engaging with the latest controversies and debates. It reveals how ongoing discoveries of far-distant extrasolar planets and planetary systems are transforming our understanding of our own solar system's astonishing history and its possible fate.

Much of the excitement in modern Solar Physics has come from the realisation that the Sun is a plasma and that this plasma is interacting with the magnetic field in a wide variety of subtle ways. As well as being of great interest in their own right the observed plasma phenomena on the Sun are of much wider importance, since they reveal to us details of basic phenomena that are expected to be occurring throughout the universe. It was with this in mind that 173 solar physicists from 17 countries gathered together in Bangalore with an air of anticipation. We were not disappointed as we received the warmest of welcomes from our graceful and charming host, Vinod Krishan. She and her colleagues worked tirelessly to make our stay a most memorable one and to ensure that the meeting ran with calm and efficiency. In addition to being stimulated by an excellent series of talks on the up-to-the minute advances in our subject, it was a pleasure to make new friendships from so many countries and to learn, in particular, of the Solar Physics being done in India which has a great tradition and is of a high standard. Furthermore, we enjoyed hearing about Indian culture and appreciating its beauty, especially on our day's tour into the countryside to visit some Hindu and Jain temples."

This Symposium, the first devoted entirely to the measurement and the role of magnetic fields in the non-solar Universe, was held in Heidelberg, on June 19-23, 1989. The meeting began with review talks on magnetic phenomena near the solar photosphere, corona, and in stellar winds, since these nearby "laboratories," studied for many years, provide much of the prior knowl edge of magnetic effects in astrophysical plasmas. The Symposium contained presentations of considerable new work concerning the role of magnetic fields in accretion disks, bipolar outflows, and related magnetic phenomena in molecular clouds and star forming regions. Both observa tions and related theory of the large-scale magnetic fields in the Milky Way were covered, in addition to a session on the more general theme of magnetohydrodynamics of galactic magnetic fields. Dynamo mechanisms were discussed in considerable detail. It was apparent that recent observational data on polarized emission from external galaxies are now of sufficiently high quality that meaningful tests of large-scale field amplification, and of ideas on the origin of galactic magnetic fields, can be undertaken. Both new observations and numerical simulation work were described in the context of active galaxy nuclei, supernova remnants, radio source jets and extended lobes, and also in the environment of galaxy clusters. Recent large-scale computer simulations incorporating magnetic fields in star formation, radio source jets, and many other phenomena were presented, and much of this was very new."

Solar and stellar photospheres constitute the layers most accessible to observations, forming the interface between the interior and the outside of the stars. The solar atmosphere is a rich physics laboratory, in which the whole spectrum of radiative, dynamical, and magnetic processes that tranfer energy into space can be observed. As the fundamental processes take place on very small spatial scales, we need high. resolution observations to explore them. On the other hand the small-scale processes act together to form global properties of the sun, which have their origins in the solar interior. The rapid advances in observational techniques and theoreticallllodelling over the past decade made it very timely to bring together scientists from east and west to the first lAU Symposium on this topic. The physics of the photosphere involves complicated interactions between magnetic fields, convection, waves, and radiation. During the past decade our understanding of these gener ally small-scale structures and processes has been dramatically advanced. New instrumen tations, on ground and in space, have given us new means to study the granular convection. Diagnostic methods in Stokes polarimetry have allowed us to go beyond the limitations of spatial resolution to explore the structure and dynamics of the subarcsec magnetic struc tures. Extensive numerical simulations of the interaction between convection and magnetic fields using powerful supercomputers are providing deepened physical insight. Granulation, magnetic fields, and dynamo processes are being explored in the photospheres of other stars, guided by our improved understanding of the solar photosphere."

As a star, the sun is continuously emitting an enormous amount of energy 33 into space, up to as much as 3. 9 X 10 erg/ s. This energy emission consists of three modes. Almost all the energy is emitted in the form of the familiar black-body radiation, commonly called sunlight. Although the amount of energy emitted is small, the sun also emits x rays, extreme ultraviolet (EUV), and UV radiations, which are absorbed above the earth's stratosphere. These constitute the second mode of solar energy, separate from the black-body radiation that penetrates the lower layers of the atmosphere. The sun has another important mode of energy emission in which the energy is carried out by charged particles. These particles have a very wide range of energies, from less than I keY to more than I GeV. Because of this wide range, it is convenient to group them into two components: particles with energies greater than 10 keY and the lower-energy particles. The former are generally referred to as solar protons or solar cosmic rays; their emission is associated with active features on the sun. Their interaction with the atmosphere is similar to that of the x ray and EUV radiation. Low-energy particles constitute plasma, a gas of equal numbers of positive and negative particles. Actually, this plasma is the outermost part of the solar atmosphere, namely the corona, which blows out continuously . For this reason, the plasma flow is called the solar wind.

Stellar flares represent one of the most challenging problems of contemporary astrophysics. Both solar and stellar observations have shown the flare phenomenon to be very complex, and in recent years important progress has been made from simultaneous observations over wide wavelength ranges. Some similarities exist between solar and stellar flares, but im portant differences have also been established. Such topics, as well as theoretical aspects, were discussed in detail at the Palo Alto IAU Colloquium No. 104, Solar and Stellar Flares, in 1988. Another approach to the study of stellar flares is through observations of flare stars in physical systems. The possibility of detecting flare stars in star clusters and associations with wide angle telescopes have allowed observations of systems with quite different ages. The classical works of G. Haro and V. A. Ambartsumian demonstrated the evolutionary nature of the flare phenomenon. Flares occur at the earliest stages of dwarf star evolution. The photographic observations of flare stars in systems of different ages turned out to be significant not only for the evolutionary study of flare stars, but also for the study of their physical nature. This observational fact was conditioned by very large diversity of flare star luminosities, i.e. of scales of flares produced by them and by peculiarities of stellar flares observed in star clusters and associations."

Prominences are amazing objects of great beauty whose formation, basic structure and eruption represent one of the basic unsolved problems in Solar Physics. It is now 14 years since the last book on prominences appeared (Tandberg-Hanssen, 1974), during which time much progress in our knowledge of the physics of prominences has been made, and so the time is ripe for a new text book which it is hoped will be a helpful summary of the subject for students, postdocs and solar researchers. Indeed, the last few years has seen an upsurge in interest in prominences due to high resolution ground-and space-based observations and advances in theory. For example, an IAU colloquium was held in Oslo (Jensen et al, 1978), a Solar Maximum Mission Workshop took place at Goddard Space Right Center (poland, 1986), an IAU Colloquium is planned in Yugoslavia in September 1989 in prominences and it is expected that the SOHO satellite will be a further stimulus to prominence research. In November 1987 a Workshop on the Dynamics and Structure of Solar Prominences was held in Palma Mallorca at the invitation of Jose Luis Ballester with the aim of bringing observers and theorists together and having plenty of time for in-depth discussions of the basic physics of promi nences."

Helio- and asteroseismology study the interior of the Sun and other stars, by means of observations of oscillations on their surfaces. The last 10 years in the study of the solar interior, to a has witnessed a very rapid evolution point where we can now contemplate investigating the physical state of matter, or the details of rotation and other large-scale motion, in the Sun. The stellar studies are in some respects at the point of the solar studies 10 years ago, but appear poised to take off. Thus the time was deemed ripe for lAO Symposium No 123, to assess the present status of this work, and plan for its future development. Apart from the seismic data, few observations are available to provide information about stellar interiors. Detailed studies, by spectral analysis, can be made of stellar surface properties, including atmospheric temperature and chemical composition. However, the stellar radiative spectrum is almost entirely fixed by the mass, luminosity, radius and surface rotation of the star, and contains essentially no other information about the interior. An important test of stellar evolution theory is provided by observations of stel lar clusters, whose members can reasonably be assumed to have the same age and chemical composition. The location of such stars in a HR diagram, where luminosity is plotted against the effective temperature, can roughly be understood in terms of stellar evolution calculations."