R. Kallenbach – författare

A Corotating Interaction Region (CIR) is the result of the interaction of fast solar wind with slower solar wind ahead. CIRs have a very large three-dimensional ex­ tent and are the dominant large-scale structure in the heliosphere on the declining and minimum phase of the solar activity cycle. Until recently, however, CIRs could only be observed close to the ecliptic plane, and their three-dimensional structure was therefore not obvious to observers and theoreticians alike. Ulysses was the first spacecraft allowing direct exploration of the third dimen­ sion of the heliosphere. Since 1992, when it has entered a polar orbit that takes it 0 up to 80 latitude, the spacecraft's performance has been flawless and the mission has provided excellent data from a superbly matched set of instruments. Perhaps the most exciting observation during Ulysses' first passage towards the south pole of the Sun was a strong and long lasting CIR whose energetic particle effects were observed up to unexpectedly high latitudes. These observations, documented in a number of publications, stimulated considerable new theoretical work.

The workshop "From Dust to Terrestrial Planets" was initiated by a working group of planetary scientists invited to ISSI by Johannes Geiss in November 1997. The group split to focus on three topics, one of which was the history of the early solar system, including the formation of the terrestrial planets in the inner solar system. Willy Benz, Gunter Lugmair, and Frank Podosek were invited to convene planetary scientists, astrophysicists, and cosmochemists to synthesize the current knowledge on the origin and evolution of our inner planetary system. The convenors raised the interest of scientists from all over the world in the detailed assessment of the available astronomical, chronological, geochemical and dynamical constraints of the first period of inner solar system evolution. In partic­ ular, this included appraisal of the newest results from astronomical observations by the Hubble Space Telescope, the Infrared Space Observatory, and other space and ground-based facilities of solar-like systems and nebular disks, possibly repre­ senting early stages of the solar accretion disk and planet formation. At the same time, the current models of the origin, evolution, transport, and accretion processes of circum stellar disks were presented. This included the new insights provided by the recent discovery of extrasolar giant planets, which were considered insofar as they are relevant to the overall dynamics of the inner part of the solar system.

The year 1998 marked the 50th anniversary of the invention of the neutron monitor, a key research tool in the field of space physics and solar-terrestrial relations. In honor of this occasion a workshop entitled 'Cosmic Rays and Earth' was organized to review the detection of cosmic rays at the surface and in the lower atmosphere of Earth, including the effect that this radiation has on the terrestrial environment. A special focus was the role of neutron monitors in the investigation of this radiation, on the science enabled by the unique dataset of the worldwide network of neutron monitors, and on continuing opportunities to use these data to solve outstanding problems. This book is the principal product of that workshop, integrating the contribu­ tions of all participants. Following a general summary of the workshop prepared by the editors, the volume leads off with a keynote article by Professor John Simpson describing his invention of the neutron monitor in 1948 and the early scientific discoveries made with this instrument.

Mars is about one-eighth the mass of the Earth and it may provide an analogue of what the Earth was like when it was at such an early stage of accretion. The fur­ ther growth of the Earth was sustained by major collisions with planetesimals and planets such as that which resulted in the formation ofthe Earth's moon (Hartmann and Davis, 1975; Cameron and Ward, 1976; Wetherill, 1986; Cameron and Benz, 1991). This late accretionary history, which lasted more than 50 Myr in the case of the Earth (Halliday, 2000a, b), appears to have been shorter and less catastrophic in the case of Mars (Harper et ai. , 1995; Lee and Halliday, 1997). In this article we review the basic differences between the bulk composition of Mars and the Earth and the manner in which this plays into our understanding of the timing and mechanisms of accretion and core formation. We highlight some of the evidence for early cessation of major collisional growth on Mars. Finally, we reevaluate the isotopic evidence that Mars differentiated quickly. Fundamental differences between the composition of Mars and that of other terrestrial planets are apparent from the planet's slightly lower density and from the compositions of Martian meteorites. The low density is partially explicable if there is a greater proportion of more volatile elements.

This volume, together with those on "Cosmic Rays in the Heliosphere" and on "Cosmic Rays at Earth", rounds off a trilogy devoted to cosmic rays. It specifically deals with the astrophysical sources and acceleration processes of cosmic rays. The principal aims are to examine the cosmic ray phenomenon in the context of our evolving understanding of the Galaxy as an astrophysical system. Observations of cosmic rays, and theoretical models of their origin and propagation, are critically reviewed. The extent to which these reinforce, or conflict with, other astronomical information about the Galaxy is addressed.

This volume, number 16 in the Space Sciences Series of ISSI, reviews the present knowledgeonmanyaspectsofthehistoryofthesolarsystem. Itfocuses onisotopic signatures ofvolatile elements as tracers for the evolutionary processes during the formation of the Sun and the planets from an interstellar molecular cloud and, in tum, illuminates how the isotopic compositions of present-day solar system ob- jects had been established. This integrated collection of articles complements the information provided by previous ISSI volumes such as From Dust to Terrestrial Planets and Chronology and Evolution of Mars, expanding the time scale for the history ofthe solar system. The convenors, Therese Encrenaz, Observatoire de Paris, Meudon; Johannes Geiss, ISSI, Bern; Reinald Kallenbach, ISSI, Bern; Konrad Mauersberger, Max- Planck-Institut fUr Kernphysik, Heidelberg; Tobias Owen, University of Hawaii, Honolulu; and Fran~ois Robert, CNRS-Museum d'Histoire Naturelle, Paris, in- vited experts in planetary science, solar and heliospheric physics, astrophysics, mineralogy, and chemistry to an interdisciplinary workshop in Bern, 14-18 Jan- uary 2002.The resulting review articles are grouped into four sections 'Sun and Protosolar Nebula', 'Outer Solar System', 'Earth, Terrestrial Planets, and Moon', and 'Isotopic FractionationProcesses'.

Representatives of several scientific communities, such as planetary scientists, astronomers, space physicists, chemists and astrobiologists have met with the aim to review the knowledge on four major themes: (1) the study of the formation and evolution processes of the outer planets and their satellites, beginning with the formation of compounds and planetesimals in the solar nebula, and the subsequent evolution of the interiors of the outer planets, (2) a comparative study of the atmospheres of the outer planets and Titan, (3) the study of the planetary magnetospheres and their interactions with the solar wind, and (4) the formation and properties of satellites and rings, including their interiors, surfaces, and their interaction with the solar wind and the magnetospheres of the outer planets. Beyond these topics, the implications for the prebiotic chemical evolution on Europa and Titan are reviewed.At the time of publication, the study of the outer planets is particularly motivated by the fact that the Saturn system is being investigated by the Cassini-Huygens mission.

Observing our Universe and its evolution with ever increasing sensitivity from ground-based or space-borne telescopes is posing great challenges to Fundamental Physics and Astronomy. The remnant cosmic microwave background, as beautifully measured by successive space missions COBE, WMAP, and now PLANCK, provides a unique probe of the very early stages of our Universe. The red-shift of atomic lines in distant galaxies, the dynamics of pulsars, the large scale structure of galaxies, and black holes are a few manifestations of the theory of General Relativity. Yet, today, we understand only 4% of the mass of our Universe, the rest being called dark energy and dark matter, both of unknown origin! A second family of space missions is currently emerging; rather than designing ever more re nedobservationalinstruments,physicistsandengineersseekalsotousethespaceenvironment to perform high-precision tests of the fundamental laws of physics. The technology required for such tests has become available only over the course of the last decades. Clocks of high accuracy are an example. They are based on advances in atomic and laser physics, such as cold atoms, enabling a new generation of highly sensitive quantum sensors for ground and space experiments. Two experiments in space have now tested Einstein’s relativity theory: • Several decades ago, Gravity Probe A con rmed the accuracy of the gravitational red-shift ?5 according to general relativity to a level of 7× 10 [R. F. C. Vessot et al. , Test of Relativistic Gravitation with a Space-Borne Hydrogen Maser, Phys. Rev. Lett. 45, 2081–2084 (1980)].

Observing our Universe and its evolution with ever increasing sensitivity from ground-based or space-borne telescopes is posing great challenges to Fundamental Physics and Astronomy. The remnant cosmic microwave background, as beautifully measured by successive space missions COBE, WMAP, and now PLANCK, provides a unique probe of the very early stages of our Universe. The red-shift of atomic lines in distant galaxies, the dynamics of pulsars, the large scale structure of galaxies, and black holes are a few manifestations of the theory of General Relativity. Yet, today, we understand only 4% of the mass of our Universe, the rest being called dark energy and dark matter, both of unknown origin! A second family of space missions is currently emerging; rather than designing ever more re nedobservationalinstruments,physicistsandengineersseekalsotousethespaceenvironment to perform high-precision tests of the fundamental laws of physics. The technology required for such tests has become available only over the course of the last decades. Clocks of high accuracy are an example. They are based on advances in atomic and laser physics, such as cold atoms, enabling a new generation of highly sensitive quantum sensors for ground and space experiments. Two experiments in space have now tested Einstein’s relativity theory: • Several decades ago, Gravity Probe A con rmed the accuracy of the gravitational red-shift ?5 according to general relativity to a level of 7× 10 [R. F. C. Vessot et al. , Test of Relativistic Gravitation with a Space-Borne Hydrogen Maser, Phys. Rev. Lett. 45, 2081–2084 (1980)].

A Corotating Interaction Region (CIR) is the result of the interaction of fast solar wind with slower solar wind ahead. CIRs have a very large three-dimensional ex­ tent and are the dominant large-scale structure in the heliosphere on the declining and minimum phase of the solar activity cycle. Until recently, however, CIRs could only be observed close to the ecliptic plane, and their three-dimensional structure was therefore not obvious to observers and theoreticians alike. Ulysses was the first spacecraft allowing direct exploration of the third dimen­ sion of the heliosphere. Since 1992, when it has entered a polar orbit that takes it 0 up to 80 latitude, the spacecraft's performance has been flawless and the mission has provided excellent data from a superbly matched set of instruments. Perhaps the most exciting observation during Ulysses' first passage towards the south pole of the Sun was a strong and long lasting CIR whose energetic particle effects were observed up to unexpectedly high latitudes. These observations, documented in a number of publications, stimulated considerable new theoretical work.

This book summarizes the results from the detection of cosmic rays at the surface and in the lower atmosphere of Earth during the fifty years since the invention of the neutron monitor by John A. Simpson in 1948. The properties of solar and galactic cosmic rays in the heliosphere, such as Forbush decreases, modulations by solar and heliosphere parameters, the physical processes that govern them, and their connection to Space Weather, are reviewed. This interdisciplinary compilation provides links between cosmic ray physics, geophysics, terrestrial climate, and human activity and health.

Mars is about one-eighth the mass of the Earth and it may provide an analogue of what the Earth was like when it was at such an early stage of accretion. The fur­ ther growth of the Earth was sustained by major collisions with planetesimals and planets such as that which resulted in the formation ofthe Earth's moon (Hartmann and Davis, 1975; Cameron and Ward, 1976; Wetherill, 1986; Cameron and Benz, 1991). This late accretionary history, which lasted more than 50 Myr in the case of the Earth (Halliday, 2000a, b), appears to have been shorter and less catastrophic in the case of Mars (Harper et ai. , 1995; Lee and Halliday, 1997). In this article we review the basic differences between the bulk composition of Mars and the Earth and the manner in which this plays into our understanding of the timing and mechanisms of accretion and core formation. We highlight some of the evidence for early cessation of major collisional growth on Mars. Finally, we reevaluate the isotopic evidence that Mars differentiated quickly. Fundamental differences between the composition of Mars and that of other terrestrial planets are apparent from the planet's slightly lower density and from the compositions of Martian meteorites. The low density is partially explicable if there is a greater proportion of more volatile elements.

R. DIEHL, R. KALLENBACH, E. PARIZOT and R. VON STEIGER / The Astrophysics of Galactic Cosmic Rays 3 I: KEY OBSERVATIONS ON GALACTIC COSMIC RAYS M. E. WIEDENBECK, N. E. YANASAK, A. c. CUMMINGS, AJ. DAVIS, I. S. GEORGE, R. A. LESKE, R. A. MEWALDT, E. C. STONE, P. L. HINK, M. H. ISRAEL, M. LIJOWSKI, E. R. CHRISTIAN and TT VON ROSENVINGE / The Origin of Primary Cosmic Rays: Constraints from ACE Elemental and Isotopic Composition Observations 15 R. A. MEWALDT, N. E. YANASAK, M. E. WIEDENBECK, AJ. DAVIS, w. R. BINNS, E. R. CHRISTIAN, A. C. CUMMINGS, P. L. HINK, R. A. LESKE, S. M. NIEBUR, E. C. STONE and TT VON ROSENVINGE / Radioactive Clocks and Cosmic-Ray Transport in the Galaxy 27 J. J. CONNELL / Cosmic-Ray Composition as Observed by Ulysses 41 R. RAMATY, R. E. LINGENFELTER and B. KOZLOVSKY / Spallogenic Light Elements and Cosmic-Ray Origin 51 E. PARIZOT / Galactic Cosmic Rays and the Light Elements 61 G. MEYNET, M. ARNOULD, G. PAULUS and A. MAEDER / Wolf-Rayet Star Nucleosynthesis and the Isotopic Composition of the Galactic Cosmic Rays 73 S. P. SWORDY / The Energy Spectra and Anisotropies of Cosmic Rays 85 G. TARLE and M. SCHUBNELL / Antiparticles 95 D. MULLER / Cosmic Rays Beyond the Knee 105 II: LESSONS FROM THE HELIOSPHERE G. M. MASON / Heliospheric Lessons for Galactic Cosmic-Ray Acceleration 119 R. A.

This volume, number 16 in the Space Sciences Series of ISSI, reviews the present knowledgeonmanyaspectsofthehistoryofthesolarsystem. Itfocuses onisotopic signatures ofvolatile elements as tracers for the evolutionary processes during the formation of the Sun and the planets from an interstellar molecular cloud and, in tum, illuminates how the isotopic compositions of present-day solar system ob- jects had been established. This integrated collection of articles complements the information provided by previous ISSI volumes such as From Dust to Terrestrial Planets and Chronology and Evolution of Mars, expanding the time scale for the history ofthe solar system. The convenors, Therese Encrenaz, Observatoire de Paris, Meudon; Johannes Geiss, ISSI, Bern; Reinald Kallenbach, ISSI, Bern; Konrad Mauersberger, Max- Planck-Institut fUr Kernphysik, Heidelberg; Tobias Owen, University of Hawaii, Honolulu; and Fran~ois Robert, CNRS-Museum d'Histoire Naturelle, Paris, in- vited experts in planetary science, solar and heliospheric physics, astrophysics, mineralogy, and chemistry to an interdisciplinary workshop in Bern, 14-18 Jan- uary 2002.The resulting review articles are grouped into four sections 'Sun and Protosolar Nebula', 'Outer Solar System', 'Earth, Terrestrial Planets, and Moon', and 'Isotopic FractionationProcesses'.

The workshop "From Dust to Terrestrial Planets" was initiated by a working group of planetary scientists invited to ISSI by Johannes Geiss in November 1997. The group split to focus on three topics, one of which was the history of the early solar system, including the formation of the terrestrial planets in the inner solar system. Willy Benz, Gunter Lugmair, and Frank Podosek were invited to convene planetary scientists, astrophysicists, and cosmochemists to synthesize the current knowledge on the origin and evolution of our inner planetary system. The convenors raised the interest of scientists from all over the world in the detailed assessment of the available astronomical, chronological, geochemical and dynamical constraints of the first period of inner solar system evolution. In partic­ ular, this included appraisal of the newest results from astronomical observations by the Hubble Space Telescope, the Infrared Space Observatory, and other space and ground-based facilities of solar-like systems and nebular disks, possibly repre­ senting early stages of the solar accretion disk and planet formation. At the same time, the current models of the origin, evolution, transport, and accretion processes of circum stellar disks were presented. This included the new insights provided by the recent discovery of extrasolar giant planets, which were considered insofar as they are relevant to the overall dynamics of the inner part of the solar system.

The workshop "From Dust to Terrestrial Planets" was initiated by a working group of planetary scientists invited to ISSI by Johannes Geiss in November 1997. The group split to focus on three topics, one of which was the history of the early solar system, including the formation of the terrestrial planets in the inner solar system. Willy Benz, Gunter Lugmair, and Frank Podosek were invited to convene planetary scientists, astrophysicists, and cosmochemists to synthesize the current knowledge on the origin and evolution of our inner planetary system. The convenors raised the interest of scientists from all over the world in the detailed assessment of the available astronomical, chronological, geochemical and dynamical constraints of the first period of inner solar system evolution. In partic­ ular, this included appraisal of the newest results from astronomical observations by the Hubble Space Telescope, the Infrared Space Observatory, and other space and ground-based facilities of solar-like systems and nebular disks, possibly repre­ senting early stages of the solar accretion disk and planet formation. At the same time, the current models of the origin, evolution, transport, and accretion processes of circum stellar disks were presented. This included the new insights provided by the recent discovery of extrasolar giant planets, which were considered insofar as they are relevant to the overall dynamics of the inner part of the solar system.

Mars is about one-eighth the mass of the Earth and it may provide an analogue of what the Earth was like when it was at such an early stage of accretion. The fur­ ther growth of the Earth was sustained by major collisions with planetesimals and planets such as that which resulted in the formation ofthe Earth''s moon (Hartmann and Davis, 1975; Cameron and Ward, 1976; Wetherill, 1986; Cameron and Benz, 1991). This late accretionary history, which lasted more than 50 Myr in the case of the Earth (Halliday, 2000a, b), appears to have been shorter and less catastrophic in the case of Mars (Harper et ai. , 1995; Lee and Halliday, 1997). In this article we review the basic differences between the bulk composition of Mars and the Earth and the manner in which this plays into our understanding of the timing and mechanisms of accretion and core formation. We highlight some of the evidence for early cessation of major collisional growth on Mars. Finally, we reevaluate the isotopic evidence that Mars differentiated quickly. Fundamental differences between the composition of Mars and that of other terrestrial planets are apparent from the planet''s slightly lower density and from the compositions of Martian meteorites. The low density is partially explicable if there is a greater proportion of more volatile elements.

A Corotating Interaction Region (CIR) is the result of the interaction of fast solar wind with slower solar wind ahead. CIRs have a very large three-dimensional ex­ tent and are the dominant large-scale structure in the heliosphere on the declining and minimum phase of the solar activity cycle. Until recently, however, CIRs could only be observed close to the ecliptic plane, and their three-dimensional structure was therefore not obvious to observers and theoreticians alike. Ulysses was the first spacecraft allowing direct exploration of the third dimen­ sion of the heliosphere. Since 1992, when it has entered a polar orbit that takes it 0 up to 80 latitude, the spacecraft''s performance has been flawless and the mission has provided excellent data from a superbly matched set of instruments. Perhaps the most exciting observation during Ulysses'' first passage towards the south pole of the Sun was a strong and long lasting CIR whose energetic particle effects were observed up to unexpectedly high latitudes. These observations, documented in a number of publications, stimulated considerable new theoretical work.

The year 1998 marked the 50th anniversary of the invention of the neutron monitor, a key research tool in the field of space physics and solar-terrestrial relations. In honor of this occasion a workshop entitled ''Cosmic Rays and Earth'' was organized to review the detection of cosmic rays at the surface and in the lower atmosphere of Earth, including the effect that this radiation has on the terrestrial environment. A special focus was the role of neutron monitors in the investigation of this radiation, on the science enabled by the unique dataset of the worldwide network of neutron monitors, and on continuing opportunities to use these data to solve outstanding problems. This book is the principal product of that workshop, integrating the contribu­ tions of all participants. Following a general summary of the workshop prepared by the editors, the volume leads off with a keynote article by Professor John Simpson describing his invention of the neutron monitor in 1948 and the early scientific discoveries made with this instrument.