This book is a historical-epistemological study of one of the most consequential breakthroughs in the history of celestial mechanics: Robert Hooke's (1635-1703) proposal to "compoun[d] the celestial motions of the planets of a direct motion by the tangent & an attractive motion towards a centrat body" (Newton, The Correspondence li, 297. Henceforth: Correspondence). This is the challenge Hooke presented to Isaac Newton (1642-1727) in a short but intense correspondence in the winter of 1679-80, which set Newton on course for his 1687 Principia, transforming the very concept of "the planetary heavens" in the process (Herivel, 301: De Motu, Version III). 1 It is difficult to overstate the novelty of Hooke 's Programme * The celestial motions, it suggested, those proverbial symbols of stability and immutability, werein fact a process of continuous change: a deflection of the planets from original rectilinear paths by "a centraU attractive power" (Correspondence, li, 313). There was nothing necessary or essential in the shape of planetary orbits. Already known to be "not circular nor concentricall" (ibid. ), Hooke claimed that these apparently closed "curve Line[ s ]" should be understood and calculated as mere effects of rectilinear motions and rectilinear attraction. And as Newton was quick to realize, this also implied that "the planets neither move exactly in ellipse nor revolve twice in the same orbit, so that there are as many orbits to a planet as it has revolutions" (Herivel, 301: De Motu, Version III).

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.

9 MHDTurbulence in the Heliosphere: Evolution and Intermittency 253 Bruno Bavassano, Roberto Bruno and Vincenzo Carbone 1 Introduction 254 2 MHD Turbulence Evolution 255 2. 1 Ecliptic Turbulence 256 2. 2 Polar Turbulence 258 2. 3 Conclusions on Turbulence Evolution 263 3 Intermittency 264 3. 1 Probability Distribution Functions of Fluctuations and Self-similarity 269 3. 2 Radial Evolution of Intermittency 271 3. 3 Identifying Intermittent Events 273 3. 4 Conclusions on Intermittency 277 10 283 Waves and Turbulence in the Solar Corona Eckart Marsch 1 Introduction 284 2 Coronal Magnetic Field Structures 284 3 Magnetic Network Activity and Coronal Heating 287 4 Waves and Flows in Loops and Funnels 290 5 Magnetohydrodynamic Waves and Flux Tube Oscillations 293 5. 1 Observation and Theory 293 5. 2 Oscillations of Thin Flux Tubes 295 5. 3 Wave Amplitudes Versus Height from Numerical Mod- ~ 2~ 5. 4 A Standing Slow Magnetoacoustic Wave 299 6 Plasma Waves and Heating of Particles 301 7 Generation, Transfer and Dissipation of Coronal Turbulence 303 7. 1 Generation of Magnetohydrodynamic Waves 303 7. 2 Wave Energy Transfer and Turbulent Cascade 304 7. 3 Wave Dissipation in the Kinetic Domain 307 7. 4 Origin and Generation of Coronal High-Frequency Waves 308 7.

New Horizons: Reconnaissance of the Pluto-Charon System and the Kuiper Belt C. T. Russell Originally published in the journal Space Science Reviews, Volume 140, Nos 1-4, 1-2. DOI: 10. 1007/s11214-008-9450-0 (c) Springer Science+Business Media B. V. 2008 Exploration is mankind's imperative. Since the beginnings of civilization, men and women have not been content to build a wall around their settlements and stay within its con nes. They explored the land around them, climbed the mountains, and scanned the horizons. The boldest among them pushed exploration to the most distant frontiers of the planet. As a result, much of the Earth was inhabited well before the days of the renowned European - th th plorers of the 15 and 16 centuries. Exploration did not cease, after the circumnavigation of the globe; it continued to the present. Today explorers are going in new directions, not just east and west, north and south. They explore backward in time and upward in space. Arc- ology explores the shorter time scales, and geochemistry the longer time scales of geophy- cal events: asteroidal and cometary collisions, magnetic reversals, continental formation and more. However, on Earth we cannot go back inde nitely, for much of the evidence of the very earliest days has been lost.

The theory of stellar atmospheres is one of the most important branches of modern astrophysics. It is first of all a major tool for understanding all aspects of stars. As the physical properties of their outer layers can now be found with high precision, firm conclusions can be drawn about the internal structure and evolution of stars. Moreover, improvements in our knowledge of the chemical composition of stars is shedding new light on the chemical evolution of galaxies and of the Universe as a whole. Because the outer layers of stars are among the best-understood astrophysical objects, the theory of stellar atmospheres plays an important role in the study of many other types of objects. These include planetary nebulae, H II regions, interstellar matter, and objects of interest in high-energy astrophysics, such as accretion disks (close binaries, dwarf novae, cataclysmic variables, quasars, active galactic nuclei), pulsar magnetospheres, and Seyfert galaxies. Finally, as stars provide a laboratory in which plasmas can be studied under more extreme conditions than on earth, the study of stellar atmospheres has strong connections with modern physics. Astronomical observations provided a vital stimulus in the early stages of quantum theory and atomic physics; even today topics such as low-temperature dielectronic recombination develop hand in hand with the interpretation of stellar and nebular spectra. Early work on MHD was similiarly motivated. Many such connections remain to be explored.

This volume consists of invited lectures and seminars presented at the NATO Advanced Study Institute "The Gamma Ray Sky with COMPTON GRO and SIGMA," which was held at the Centre de Physique Theorique of Les Houches (France) in January / February 1994. The school has been planned by a Scientific Organizing Committee. It was organized with the aim of providing students and young researchers with an up-to-date account of the high-energy phenomena in the vicinity of compact objets and the diffuse gamma-ray backgrounds after the early results from the gamma-ray telescope SIGMA and the four instruments onboard COMPTON GRO (Gamma Ray Observatory): BATSE (Burst and Transient Source Experiment), COMPTEL(Compto'l Telescope), EGRET (Energetic Gamma Ray Experiment Telescope) and OS SE(Oriented Scintillation Spectrometer Experiment) . It was attended by more than sixty researchers from many countries. The lectures and seminars represent a complete coverage of our present knowledge and understanding of: Gamma-ray backgrounds, Gamma-ray Burts, Active Galactic Nuclei, Galactic Compact Objects, Gamma-ray Spectroscopy, Instrumentation and observation techniques, etc ... Most of these lectures are reproduced in this volume. Unfortunately, a few lecturers have chosen not to submit their manuscript.

The general background of this monograph and the aim of it is described in detail in Chapter I. As stated in 1.7 it is written according to the principle that "when rigour appears to conflict with simplicity, simplicity is given preference," which means that it is intended for a rather broad public. Not only graduate students but also advanced undergraduates should be able to understand at least most of it. This monograph is the result of many years of inspiring discussions with a number of colleagues, for which I want to thank them very much. Especially I should mention the groups in Stockholm and La Jolla: in Stockholm, Dr Carl-Gunne Flilthammar and many of his collaborators, including Drs Lars Block, Per Carlqvist, Lennart lindberg, Michael Raadu, Staffan Torven, Miroslav Babic, and Itlgvar Axniis, and further, Drs Bo Lehnert and Bjorn Bonnevier, all at the Royal Institute of Technology. Of other col leagues in Sweden, I should mention Dr Bertel Laurent, Stockholm University, Dr Aina Elvius, The Stockholm Observatory, and Dr Bengt Hultqvist, Kiruna. In La Jolla my thanks go first of all to Dr Gustaf Arrhenius, who once invited me to La Jolla, which was the start of a most interesting collaboration; further, to Dr W. B."

Over the last decade we have witnessed a rapid change in our understanding of the late stages of stellar evolution. A major stimulus to this has been the synthesis of observational data from different wavebands of the electromagnetic spectrum. The advent of infrared astronomy has led to the discovery of many luminous. late-type stars obscured by their circumstellar dust envelope. Sources discovered in the IRC and AFGL infrared sky surveys were followed up by radio observa tions, leading to the widespread use of the OH and CO molecules as probes of the circumstellar envelopes. Advances in the technique of aperture synthesis have made possible observations with unprecedent resolving power, both in spectral-line and continuum. The success of the recent IRAS sky survey, with the detection of over 250,000 sources, brings the promise of even more exciting years ahead. This area of astronomical research is also blessed with the close collaboration between theorists and observers. New ideas are constantly being quantitatively tested by new data. Theoretical predictions are eagerly used as guides for further observations. This conference was initiated with the following objective: bring together workers in optical, infrared, radio and theoretical astronomy and let them confront each other. Based on the post-conference res ponses we received, many of the participants have indeed found this Workshop a stimulating experience. The Workshop on the Late Stages of Stellar Evolution was held from 2-5 June 1986 in Calgary, Canada."

This book represents Volume II of the Proceedings of the UN/ESA/NASA Workshop on the International Heliophysical Year 2007 and Basic Space Science, hosted by the National Astronomical Observatory of Japan, Tokyo, 18 - 22 June, 2007. It covers two programme topics explored in this and past workshops of this nature: (i) non-extensive statistical mechanics as applicable to astrophysics, addressing q-distribution, fractional reaction and diffusion, and the reaction coefficient, as well as the Mittag-Leffler function and (ii) the TRIPOD concept, developed for astronomical telescope facilities.

The companion publication, Volume I of the proceedings of this workshop, is a special issue in the journal Earth, Moon, and Planets, Volume 104, Numbers 1-4, April 2009.

Mergers are the mechanisms by which galaxy clusters are assembled through the hierarchical growth of smaller clusters and groups. Major cluster mergers are the most energetic events in the Universe since the Big Bang. Many of the observed properties of clusters depend on the physics of the merging process. These include substructure, shock, intra cluster plasma temperature and entropy structure, mixing of heavy elements within the intra cluster medium, acceleration of high-energy particles, formation of radio halos and the effects on the galaxy radio emission.

This book reviews our current understanding of cluster merging from an observational and theoretical perspective, and is appropriate for both graduate students and researchers in the field.

This unique text discusses the mathematical principles behind Megalithic stone circles, and how these were used for observing lunar cycles in prehistoric times. The author, A. Thom, shows that stone circles were precisely planned and laid out in accordance with certain geometric figures in the classic Pythagorean tradition. Containing some mathematical and astronomical details, along with notes on site survey and location, this book is ideal for amateur enthusiasts and academicians of archaeology, astronomy, and mathematics.

Simon Murphy's thesis has significant impact on the wide use of the revolutionary Kepler Mission data, leading to a new understanding in stellar astrophysics. It first provides a deep characterisation and comparison of the Kepler long cadence and short cadence data, with particular insight into the Kepler reduction pipeline. It then brings together modern reviews of rotation and peculiarities in A-type stars, and their relationship with the pulsating delta Scuti stars. This is the first combined review of these subjects since the classic monograph by Sydney Wolff, "The A stars," was published three decades ago. The thesis presents a novel technique, Super-Nyquist Asteroseismology, that has opened up the asteroseismic study of thousands of Kepler stars. It shows case studies of delta Scuti stars examining amplitude growth, super-Nyquist pulsation, and pulsation in a high-amplitude, population II SX Phoenicis star in a 343-d binary. This work informs our understanding of the relation of rotation to peculiarity, hence has applications to atomic diffusion theory. This is a brilliant thesis written in an elegant and engaging style.

Everyone knows that the universe is extremely old and extremely large. But how did scientists determine just how old and how large? How do astronomers know that there are upwards of 100 billion galaxies in the universe if the nearest one is over 40,000 light-years away? How do we know what the stars are made of? The answer is that our current knowledge of the universe has arisen from the work and ideas of scientists and philosophers over hundreds of years. While it's only been during the last several decades that scientists have had the technology and theories to really understand how the universe works, humans have thought about such issues for millennia. And the scientists who today are attempting to understand the most complex issues of the universe build upon the work and thought of the thinkers of the last hundreds of years. The Cosmos: A Historical Perspective provides an accessible introduction to the many ways humans have conceived of the universe throughout history and what ideas have led to our current understanding of the cosmos. The book examines: BLThe Scientific Revolution and the new ideas of the Earth's place in the cosmos BLThe importance of nineteenth-century physics and chemistry in determining the compositions of stars BLEinstein's Theory of Relativity and how it altered how scientists thought about gravity BLNew, cutting-edge science that may alter, yet again, our conceptions of the cosmos, such as the inflationary universe and the possibility of "dark energy." BLJargon and mathematics is kept to a minimum, and the volume includes an annotated bibliography and a timeline. The Cosmos is an ideal introduction for students studying space science and the history andnature of the scientific understanding of the universe.

ix Fully aware of the work accomplished by Mgr. Lemattre, His Majesty King Baudouin enhanced this occasion by placing it under His High Patronage. His Holiness the Pope Jean-Paul II accepted to testify his paternel solicitude for the work of the scientists participating in the symposium. The President of the pontifical Academy of Sciences and the Director of the Vatican Observatory transmitted their fervent wishes for the full success of the symposium. Numerous other eminent people graced the ceremony with their patronage. The academic opening, the addresses of which are pub*lished by the Revue des Questions Scientifiques de Bruxelles , was presided over by Mgr. E. Massaux, Rector of the Catholic University of Louvain who spoke about Lemattre, the University professor. Professor Ch. de Duve, Nobel Prize winner in Medicine, called to mind the role of Lemattre as President of the Pontifical Academy of Sciences; the Emeritus Professor O. Godart, founder of the Institute, recalled the life and work of Mgr. Lemattre; Professor A. Deprit, Senior Mathematician at the National Bureau of Standards, spoke about Lemattre' s work in celestial mechanics and his keen interest for computers; Professor J. Peebles, Professor of Physics at Princeton University, summarized the fundamental contributions of Lemattre to modern cosmology. The attendance of more than three hundred people was enhanced by the presence of Mgr. A. Pedroni, Papal Nuncio, Mr Ph. Maystadt, Minister of Research Policy, Mr E. Knoops, Secretary of State, Mr Y. de Wasseige, Senator, Professor E.

Ya. B. Zeldovich was most assuredly one of the greatest physicists and cosmologists of the 20th century. This volume presents reminiscences about this exemplary academician, providing biographical and historical insights from the friends, students, and colleagues who knew him best. They outline Zeldovich's life and achievements, from his early days in chemical physics through his groundbreaking work in combustion and detonation, his role in the development of Soviet nuclear and thermonuclear weapons, and his contributions to nuclear and elementary particle physics, to his later years in cosmology and astrophysics. Zeldovich: Reminiscences not only pays homage to an outstanding scientist and his accomplishments. It also offers incisive commentary on Soviet science and the impact that Zeldovich had on future generations, in the former Soviet Union and throughout the international physics community.

A new and detailed picture of Mercury is emerging thanks to NASA's MESSENGER mission that spent four years in orbit about the Sun's innermost planet. Comprehensively illustrated by close-up images and other data, the author describes Mercury's landscapes from a geological perspective: from sublimation hollows, to volcanic vents, to lava plains, to giant thrust faults. He considers what its giant core, internal structure and weird composition have to tell us about the formation and evolution of a planet so close to the Sun. This is of special significance in view of the discovery of so many exoplanets in similarly close orbits about their stars. Mercury generates its own magnetic field, like the Earth (but unlike Venus, Mars and the Moon), and the interplay between Mercury's and the Sun's magnetic field affects many processes on its surface and in the rich and diverse exosphere of neutral and charged particles surrounding the planet. There is much about Mercury that we still don't understand. Accessible to the amateur, but also a handy state-of-the-art digest for students and researchers, the book shows how our knowledge of Mercury developed over the past century of ground-based, fly-by and orbital observations, and looks ahead at the mysteries remaining for future missions to explore.

Most of the visible matter in the universe exists in the plasma state. Plasmas are of major importance for space physics, solar physics, and astrophysics. On Earth they are essential for magnetic controlled thermonuclear fusion.

This textbook collects lecture notes from a one-semester course taught at the K.U. Leuven to advanced undergraduate students in applied mathematics and physics. A particular strength of this book is that it provides a low threshold introduction to plasmas with an emphasis on first principles and fundamental concepts and properties.

The discussion of plasma models is to a large extent limited to Magnetohydrodynamics (MHD) with its merits and limitations clearly explained. MHD provides the students on their first encounter with plasmas, with a powerful plasma model that they can link to familiar classic fluid dynamics. The solar wind is studied as an example of hydrodynamics and MHD at work in solar physics and astrophysics.

Space debris and asteroid impacts pose a very real, very near-term threat to Earth. In order to help study and mitigate these risks, the Stardust program was formed in 2013. This training and research network was devoted to developing and mastering techniques such as removal, deflection, exploitation, and tracking. This book is a collection of many of the topics addressed at the Final Stardust Conference, describing the latest in asteroid monitoring and how engineering efforts can help us reduce space debris. It is a selection of studies bringing together specialists from universities, research institutions, and industry, tasked with the mission of pushing the boundaries of space research with innovative ideas and visionary concepts. Topics covered by the Symposium: Orbital and Attitude Dynamics Modeling Long Term Orbit and Attitude Evolution Particle Cloud Modeling and Simulation Collision and Impact Modelling and Simulation, Re-entry Modeling and Simulation Asteroid Origins and Characterization Orbit and Attitude Determination Impact Prediction and Risk Analysis, Mission Analysis-Proximity Operations, Active Removal/Deflection Control Under Uncertainty, Active Removal/Deflection Technologies, and Asteroid Manipulation

The story of how an eleven-year old boy growing up in 16th century Italy loses his birthday when the Gregorian calendar replaces the Julian calendar in 1582, and how he fights to prevent this loss. The author cleverly weaves elements of the cultural and scientific milieu of the time into an engaging and intelligent tale. Tibaldos father is a medical assistant, and his sister is a midwife. Thus, the boy grows up learning about current medical practices and his fascination for medicine makes him a fast learner. Then, when Tibaldo learns that he is about to lose his 13th birthday, he determines to do something about it. The result is both amusing and informative.

The concept of Stellar Populations has played a fundamental role in astronomy in the last few decades. It was introduced by Walter Baade after he was able to resolve the Andromeda Nebula and its companions into stars when he used red-sensitive plates and realised that there were two fundamentally different Herzsprung-Russell diagrams in our and these nearby galaxies (common stars in the solar neighborhood versus globular clusters). This result was published in two papers in 1944 in volume 100 of the Astrophysical Journal. Subsequent research gave the concept a much firmer basis and at the famous Vatican Symposium of 1957 resulted in a general scheme of the concept and a working hypothesis for idea's on the formation and evolution of the Galaxy. This has been a guiding principle of studies of our and other galaxies for decades. Some years ago it seemed to us appropriate to commemorate Baade's seminal work in 1994, when it would have its 50-th anniversary, and to review its present status and also its role in contempory understanding. While we were in Leiden for an administrative committee, we discussed the matter again and over beers on October 29, 1991 we decided the take the initiative for an IAU Symposium on the subject during the 1994 IAU General Assembly in Den Haag, the Netherlands.