If our eyes were radio rather than optical wide-band detectors it is well known that for us the brightest object in the sky would still be the Sun; that planets, stars and the Milky Way would still shine feebly (and that we would still occasionally be blinded by man-made sources). What is less well known is that quite a different earthbound overcast would hover about us, with its climatic zones, its seasonal changes, its unpredictable storms and scintillating transparence. To be sure, we can get a sort of glimpse of this peculiar type of weather when we tune our receiver to radio broad casting from some remote spot, or photograph the Earth from space at certain specific wavelengths. Nevertheless no one has ever looked at the ionized shroud of the Earth without the help of sophisticated apparatus, and this is one of the reasons why in this domain the phenomena are not easily abstracted from the use of specific techniques. For generations, the study of the ionosphere has been deeply interwoven with the practice of radio communication and detection. Today however, ionospheric physics is best thought of as a branch of space physics; that part of physics which deals with processes at work in the solar system and methods developed for its exploration."

The reader will find in this volume the Proceedings of the NATO Advanced Study Institute held in Maratea-Acquafredda, Italy, between June 29 and July 12, 1997, entitledTHE DYNAMICS OF SMALL BODIES IN THE SOLAR SYSTEM: A MAJOR KEY TO SOLAR SYSTEM STUDIES . This Advanced Study Institute was the latest in the 'Cortina' series of NATO ASI's begun in the early 1970's firstly under the directorship of Professor Victor Szebehely and subsequently under Professor Archie Roy. All, except the latest, were held at the Antonelli Institute, Cortina d'Ampezzo, Italy. Many of those now active in the field made their first international contacts at these Institutes. The Institutes bring together many of the brightest of our young people working in dynamical astronomy, celestial mechanics and space science, enabling them to obtain an up-to-date synoptic view of their subjects delivered by lecturers of high international reputation. The proceedings from these institutes have been well-received in the internationalcommunity of research workers in the disciplines studied. The present institute included 15 series of lectures given by invited speakers and some 45 presentations made by the other participants. The majority of these contributions are includedinthese proceedings.

As it was said by one of the participants to this workshop" In our attempts to understand the spectral evolution of galaxies, we are fortunate indeed to have the ability to look back in time and observe galaxies as they were billions of years ago. Perhaos in no other discipline is it possible to gain such a direct view to hJstory. The galaxies we seek to study are remote, their light faint, and thus only recently has it become technicaJlv feasible to sample the spectra of normal luminosity galaxies at lookback times of five billion years or more" .... or, perhaps. even to see galaxies in the process of their formation. or shortly afterwards. This fourth workshop organized by the "Advanced School ot Astronomy was indeed centered on the "Spectral Evolution of Galaxies." on reviewing and discussing the relevant astrophysical processes and on assessing our current ability to model and understand the evolution of stellar populations. Following an opening session dealing with some outstanding questions of galaxy evolution. Session I addressed the specific problems of galaxy and star formation processes. topics of uncertainty and controversy to which IRAS observations may give novel perspectives. The properties of stellar populations in the local group of galaxies formed the basis of Session II. Session III dealt with the fundaments of the theory of spectral and photometrical evolution of stellar populations. and with recent developments in the theory of stellar structure. a necessary step to model and understand galactic evolution.

This book introduces the Statistical Drake Equation where, from a simple product of seven positive numbers, the Drake Equation is turned into the product of seven positive random variables. The mathematical consequences of this transformation are demonstrated and it is proven that the new random variable N for the number of communicating civilizations in the Galaxy must follow the lognormal probability distribution when the number of factors in the Drake equation is allowed to increase at will. Mathematical SETI also studies the proposed FOCAL (Fast Outgoing Cyclopean Astronomical Lens) space mission to the nearest Sun Focal Sphere at 550 AU and describes its consequences for future interstellar precursor missions and truly interstellar missions. In addition the author shows how SETI signal processing may be dramatically improved by use of the Karhunen-Loeve Transform (KLT) rather than Fast Fourier Transform (FFT). Finally, he describes the efforts made to persuade the United Nations to make the central part of the Moon Far Side a UN-protected zone, in order to preserve the unique radio-noise-free environment for future scientific use.

Physics of Planetary Rings describes striking structures of the planetary rings of Saturn, Uranus, Jupiter, and Neptune: Narrow ringlets, spiral waves, and a chain of clumps. The author has contributed essential ideas to the full understanding of planetary rings via the stability analysis of dynamical systems. The combination of a high-quality description, the set of interesting illustrations, as well as the fascinating and natural presentation will make this book of considerable interest to astronomers, physicists, and mathematicians as well as students. There is no competing text for this book so far.

Both the high level of activity in worldwide space exploration programmes and the discovery of extra-solar planets have spurred renewed interest in the physics and evolution dynamics of solar systems. The present book has grown out of a set of lectures by leading experts in the field within the framework of the well-known EADN summer schools. It addresses primarily graduate students and young researchers but will be equally useful for scientists in search of a comprehensive tutorial account that goes beyond the material found in standard textbooks.

Ptolemy's Almagest shares with Euclid's Elements the glory of being the scientific text longest in use. From its conception in the second century up to the late Renaissance, this work determined astronomy as a science. During this time the Almagest was not only a work on astronomy; the subject was defined as what is described in the Almagest. The cautious emancipation of the late middle ages and the revolutionary creation of the new science in the 16th century are not conceivable without reference to the Almagest. This text lifted European astronomy to the high standard of knowledge on which the new science flourished. Before, the Ptolemaic models of the orbits of the sun, the moon, and the planets had been refined by Arabic astronomers. They provided the structural elements with which Copernicus and Kepler ushered in the era of modern astronomy. The Almagest survived the destruction of its epicyclic representation of the planetary orbits in the conceptual traces left behind in the theories of its successors. The clear separation of the sidereal from the tropical year, the celestial coordinate systems, the concepts of time, the forms of the constellations, and brightness classifications of celestial objects are, among many other things, still part of the astronomical canon even today.

Is planet earth the end of the line, or is space itself the next stop?
Cyberspace. It's incredible, taking us to any part of the planet we want to visit. But as Paul Levinson shows in his brilliant new book, when it comes to transport, we're still stuck in the past, preferring to take our bodies with us. Whether it's trains, yachts, scooters or pogo-sticks, we're compelled to keep moving, our movements curtailed only by the earth itself. In our imaginations however, we soar way past the limits of current technology.
With a lucid but reflective style that takes in everything from robots and science fiction to religion and philosophy, Paul Levinson asks why there is a deep seated human desire to know what's 'out there'. Why, after getting a man on the moon, did the US space program develop so slowly? In a world where space is constantly repackaged, how do we know what real space is? Is our desire to get into space natural, or a religious craving, and is it a modern phenomenon, or did our ancestors also dream of escaping the clutches of Mother Earth?
Jam-packed with exciting, innovative, even revolutionary thinking about our future, Realspace is essential reading for everyone who has ever sat at their desk, gazed into the distance and imagined boarding a space shuttle...

An up-to-date progress report on the current status of solar-terrestrial relation studies with an emphasis on observations by the Russian Interball spacecraft and the Czech Magion subsatellites. Papers in the volume describe the various spacecraft in the International Solar-Terrestrial Program and the research questions that they are being used to address. The emphasis is on correlative studies employing multiple instruments and multiple spacecraft. The book begins with a description of each spacecraft active in 1998 and describes the roles they can play in correlative studies. This is followed by an up-to-date status report concerning ongoing studies of the solar wind, foreshock, bow shock, magnetopause, magnetotail, and ionosphere, with an emphasis on the observations made by the four Interball spacecraft. Readership Researchers and graduate students of space physics and astrophysics.

The Little Book of Planet Earth presents a concise description of the geological evolution of Earth from its formation. Meissner describes in detailed but accessible prose not just the planet's features, but the tools that modern geologists use to explore and track the ever-changing subterranean and surface features of the planet. With a particular gift for expressing how the forces in and around our planet constantly alter the world we live in, the author introduces lay readers to the key topics in modern earth and planetary science: the creation of Earth and its moon (as well as stars and other planets), the role of seismology in analyzing Earth's structure, the formation of mountain ranges and basins, the role of plate tectonics, the significance of Earth's magnetic field, and the complex relationship of our planet's geology to the life forms found there.

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."

The international Colloquium "Open Issues in Local Star Formation and Early Stellar Evolution" was held in Ouro Preto (Brazil) from April 05to10, 2003. TheColloquiumtookplaceinthe"ParqueMetalurgico", ' an old iron industry that has been transformed into a nice modern c- ference center. Ouro Preto is a 18th century colonial city that has been declared a Cultural Heritage of Mankind in 1980. It is situated in the hills of the State of Minas Gerais at about 100 km from Belo Horizonte. Themeeting was attended by 115 participants from 15 countries. The participants were in general very happy with the high level of the p- sentations and with the friendly ambiance of the discussions. The talks and poster sessions were focused on the physics of young stellar objects, which are being observed with increasing angular resolution provided by the new generation of telescopes, and on the processes that triggered large scale star-formation in the solar neighborhood or in the Galaxy.

This volume reviews recent progress in the study of dynamics of star clusters. The meeting focused on the enormous progress of both the observation and the theoretical modeling of star clusters. New results from the refurbished Hubble Space Telescope (HST) include the mass function down to the hydrogen burning limits, white dwarf sequence, and central density profiles of `post-collapse' clusters by star counts. On the theoretical side, this symposium saw the first direct evidence of gravothermal oscillation through N-body simulation, which was made possible by GRAPE-4, the dedicated special-purpose computer for N-body simulation. Numerical techniques to combine stellar evolution and dynamical evolution of the cluster were presented. The book will be of primary interest to astrophysicists.

Relativistic jets are a powerful, spectacular, yet poorly-understood phenomenon associated with accreting black holes and neutron stars. The question of the internal structure - matter content and magnetic field - of relativistic jets is of prime importance for our understanding of the underlying physics. The study of circular polarisation is both challenging and potentially very rewarding, and when applied to relativistic jets has the potential to probe the structure of the jets in unique ways.
This book compiles the contributions, both theoretical and observational, from a three-day workshop held in Amsterdam in July 2002, concerning the study of circular polarisation from relativistic jet sources.

This book represents the Proceedings of the NATO Advanced Study Insti tute on Formation and Evolution of Low Mass Stars held from 21 September to 2 October 1987 at Viana do Castelo, Portugal. Holding the meeting in Portugal recognized both the historical aspects and the bright future of astronomy in Portugal. In the early sixteenth century, the Portugese played an important role in the critical diffusion of classical and medieval knowledge which formed so large a part of scientific activity at that time. Navigation and course setting, brought to a high level by Portugese explorers, relied on mathematics and astronomy to produce precise tables of solar positions. In contemporary Portu gal, astronomy is the focus of renewed interest and support at the universities. It is thus particularly appropriate that the NATO Advanced Study Institute was held on the coast of the Atlantic Ocean in the friendly surroundings of the Costa Verde.

The IAU Colloquium No. 59, "The effects of mass loss on Stellar Evolution" was held on September 15-19, 1980 at the International Centre for Theoretical Physics, Miramare, Trieste (Italy), under the auspices of the IAU Executive Co~ mittee and the Italian National Council of Research. The planning of this conference began two years ago du ring the IAU Symposium No. 83 "Mass loss and evolution of 0 type stars" (Qualicum Beach, Victoria, Canada) when we felt that mass loss and its effects on the evolution of stars was too broad a subject for being confined to 0 type stars only. Therefore we thought that a conference dealing with the general problem of mass loss across the whole HR diagram would have been of interest to all people working in the field. The main idea was that bringing together Astronomers and Astrophysicists of the widest range of interests and e~ pertize - all in some way related to the problem of mass loss from stars - would have spurred thorough discussions on the many aspects and implications of this topic. We hope this goal has been achieved. Furthermore, the most recent observational and theoreti cal developments on the problem of mass loss from early ty pe stars avoided this meeting to be a simple updating of the Qualicum Beach Symposium as far as this issue is concerned.

The idea for an international symposium on the interstellar medium was first discussed at the University of Wyoming during the summer of 1984. It was obvious that the outstanding natural beauty of the Teton mountain range in northwestern Wyoming must be matched by a meeting with the broadest appeal to the astronomical community. If the meeting was to produce a book, it must likewise be an important contribution to the astronomical literature. It was for these reasons that early in the discussions, it was decided that the University should host a "school". with the invited speakers presenting tutorials on a broad range of topics involving the interstellar medium. The symposium proceedings would then be a compilation of the written versions of these presentations. It has been nearly a decade since Lyman Spitzer published his classic text on the interstellar medium and we felt the need for a school and book that would focus on the recent developments in our understanding of the inter stellar medium. Thus, we view this two-volume set as an adjunct text to Spitzer's book.

It is rare for a complete biography of an Australian scientist, particularly of an Australian woman scientist, to be published. It is rarer for such a book to be co-authored by an American. Although scientists have written discourses on the history of their discipline, it is most unusual for a scientist to write a full length biography of a colleague in his ?eld. It is also uncommon for a man to write about an Australian woman scientist; most of the work on Australian women scientists has been done by other women. However, these authors, both distinguished researchers in the ?eld of radio astr- omy, became so interested in the history of their discipline and in the career of the pioneer radio astronomer Ruby Payne-Scott that they spent some years bringing this book to fruition. Until relatively recently, Ruby Payne-Scott had been the only woman scientist mentioned brie?y in histories of Australian science or of Australian radio astronomy. This book will be an invaluable resource for anyone interested in these disciplines. Being scientists themselves, the authors explain Payne-Scott's scienti?c work in detail; therefore, the value and importance of her contributions can, for the ?rst time, be recognised, not only by historians but also by scientists.

The idea to hold a conference on the Evolution of Close-Binary X-ray sources grew in the summer of 1984. At that time we were hoping that some new results would be harvested in the months to come which would stimulate further work. We were particularly looking towards the Euro pean X-ray Observatory, EXOSAT, for new contributions. How lucky we were; quite unexpected developments took place. Just prior to the conference, quasi-periodic oscillations (now known as QPO) were discovered in three bright low-mass X-ray binaries: GX 5-1, Sco X-1, and Cyg X-2. They played an important role at the meeting. The possibility that QPOs imply a neutron star magnetic dipole field, and a neutron star rotation period in the millisecond range, received a lot of attention. This is not surprising, as it lends support to the idea, suggested earlier, that the 6-msec binary radio pulsar PSR 1953+29 evolved from a stage in which it was a bright low-mass X-ray binary. There was special interest in the possibility of white dwarf collapse into a neutron star. This is a. particularly attractive way to form the bright low-mass X-ray binaries, often referred to as galactic bulge sources. It would allow for the possibility of a very young neutron star in a very old binary system. The relatively high magnetic fields that one could infer from QPO could then be explained."

Proceedings of IAU Symposium No. 75 held in Geneva, Switzerland, September 6-10, 1976. Dedicated to Solomon Pikel'ner

This book addresses one of the most intriguing mysteries of our universe: the nature of dark matter. The results presented here mark a significant and substantial contribution to the search for new physics, in particular for new particles that couple to dark matter. The first analysis presented is a search for heavy new particles that decay into pairs of hadronic jets (dijets). This pioneering analysis explores unprecedented dijet invariant masses, reaching nearly 7 TeV, and sets constraints on several important new physics models. The two subsequent analyses focus on the difficult low dijet mass region, down to 200 GeV, and employ a novel technique to efficiently gather low-mass dijet events. The results of these analyses transcend the long-standing constraints on dark matter mediator particles set by several existing experiments.

The Encyclopedia of Cosmology, first published in 1993, recounts the history, philosophical assumptions, methodological ambiguities, and human struggles that have influenced the various responses to the basic questions of cosmology through the ages, as well as referencing important scientific theories. Just as the recognition of social conventions in other cultures can lead to a more productive perspective on our own behaviour, so too a study of the cosmologies of other times and places can enable us recognise elements of our own cosmology that might otherwise pass as inevitable developments. Apart from modern natural science, therefore, this volume incorporates brief treatments of Native American, Cave-Dweller, Chinese, Egyptian, Islamic, Megalithic, Mesopotamian, Greek, Medieval and Copernican cosmology, leading to an appreciation of cosmology as an intellectual creation, not merely a collection of facts. It is a valuable reference tool for any student or academic with an interest in the history of science and cosmology specifically.

Gravitational lensing is by now sufficiently well understood that it can be used as a tool of investigation in other astrophysical areas. Applications include the determination of the Hubble constant, probing the dark matter context of galaxies and the mapping of the universe to the identification of otherwise invisible large-scale structures. Each chapter of the book covers in a self-contained manner a subfield of gravitational lensing, with the double aim of describing in a simple way the basics of the theory and of reviewing the most recent developments as well as applications foreseen in the near future. The book will thus be particularly useful as a high-level textbook for nonspecialist researchers and advanced students wishing to become familiar with the field all the way up to the forefront of research.