Dedication List of Figures List of Tables Contributing Authors Preface Foreword Acknowledgments 1 Introduction: Paleoheliosphere versus PaleoLISM; Priscilla C. Frisch 1.1. The Underlying Query 1.2. Addressing the Query: The Heliosphere for Different Interstellar Environments 1.3. Closing Comments References 2 HeliosphericVariation inResponse toChanging Interstellar Environments; Gary P. Zank, Hans-R. Müller, Vladimir Florinski and Priscilla C. Frisch 2.1. Introduction 2.2. Basic physics of the multi-fluid model 2.3. Possible interstellar environments 2.4. Possible heliospheric configurations 2.5. Conclusions References 3 Influence of the Interstellar Magnetic Field on the Heliospheric Interface; Nikolai V. Pogorelov and Gary P. Zank 3.1. SW-LISM Interaction Problem 3.2. Superfast SW-LISM Interaction 3.3. Subfast SW-LISM Interaction 3.4. Discussion References 4 Interplanetary Conditions and Planetary Magnetospheres; Eugene N. Parker 4.1. Introduction 4.2. Future Interstellar Variations 4.3. Magnetospheric Activity 4.4. Magnetic Activity at Uranus and Neptune References 5 Long-term Variations in the Galactic Environment of the Sun; Nir J. Shaviv 5.1. Introduction 5.2. Characterizing the Physical Environment 5.3. Variations in the Galactic Environment 5.4. Records of Long Term Variations 5.5. Crater Record 5.6. Summary References 6 Short-term Variations in the Galactic Environment of the Sun; Priscilla C. Frisch and Jonathan Slavin 6.1. Overview 6.2. The Solar Journey in Space 6.3. Neighborhood Interstellar Medium 6.4. RadiativeTransfer Models of Partially Ionized Gas 6.5. Passages through Nearby Clouds 6.6. The Solar Environment and Global ISM 6.7. Summary References 7 Variations of the Interstellar Dust Distribution in the Heliosphere; Markus Landgraf 7.1. Contemporary Interstellar Dust Environment of Heliosphere 7.2. Consequences of a Changing Interstellar Environment References 8 Effects in the Inner Heliosphere Caused by Changing Conditions in the Galactic Environment; Eberhard Möbius, Maciek Bzowski, Hans-Reinhard M uller and Peter Wurz 8.1. Introduction 8.2. Observations and Modeling of Neutrals in the Contemporary Heliosphere 8.3. Interstellar Neutral Gas and its Secondary Products under Varying Interstellar Conditions References 9 Variable Terrestrial Particle Environments During the Galactic Orbit of the Sun; Hans J. Fahr, Horst Fichtner, Klaus Scherer and Olaf Stawicki 9.1. Introductory Remarks on Cosmic Rays and Climate 9.2. The Heliosphere in Different Interstellar Environments 9.3. Cosmic Ray Spectra 9.4. Consequences of Variable Particle Environments References 10 Galactic Cosmic Ray Intensities in Response to Interstellar Environments; Vladimir Florinski and Gary P. Zank 10.1. Introduction 10.2. Transport Properties of the Heliospheric Interface 10.3. Cosmic Ray Transport Model 10.4. Modulation in the Local Interstellar Cloud 10.5. Cosmic Ray Response to Interface Variability 10.6. Cosmogenic Isotope Response 10.7. Conclusion References 11 Accretion of Interstellar Material into the Heliosphere and onto Earth; Ararat Yeghikyan and Hans Fahr 11.1. How does an Interstellar Cloud Touch the Solar System and the Earth? 11.2. Change of the Ionization Degree