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Ground based high time resolution astronomical (HTRA) observations require specialised detectors. Photon counting detectors that combine high spatial resolution imaging with fast event timing capability have been a significant technical challenge. We have developed a high-temporal and -spatial resolution, high-throughput sealed tube microchannel plate detector with electronic readout as a tool for HTRA applications. The design is based on a 25 mm diameter S20 photocathode followed by a microchannel plate stack, read out by a cross delay line anode with timing and imaging electronics. The detector supports 500 kHz global count rate, 10 kHz /100 μm2/sec local count rate, and 100 ps timing resolution. We also describe high time resolution astronomical observations currently being obtained with the NASA GALEX UV satellite, as well as preliminary visible wavelength imaging results obtained on the Crab pulsar at the Lick Observatory. [ABSTRACT FROM AUTHOR]

When one spends 108-8.5 euros on a large aperture telescope, it behoves one to make maximal use of the photons concentrated at the focus. One popular path is to use very large focal plane arrays, for a high multiplex advantage; this is a natural driver in extragalactic survey science. The other avenue to efficiency applies to single source science, where a large field of view is not necessary, but energy resolution over a broad wavelength range, high time resolution and, possibly, polarization measurements wring maximum benefit from the collected photons. Cryogenic energy-resolving sensors are proving to be promising detectors for many areas of astronomy. Significant astronomical observations have, in fact, already been made using two detector schemes: Superconducting Tunnel Junction (STJ) and Transition-Edge Sensor (TES). TES instruments, in particular, have found application as bolometric detectors from the sub-mm to the hard X-ray range. We focus here on TES applications in the near IR through UV, reviewing the basic technology and describing current work toward effective imaging arrays. A TES camera using such arrays can address the need for broad-band single source efficiency at large telescopes noted above. A review of early test observations and a description of a few science goals are presented to illustrate this potential. [ABSTRACT FROM AUTHOR]

Investigative studies have designed concept instruments for a proposed 42 m European Extremely Large Telescope (E-ELT) facility suite. An ELT will aid, at its most basic level, detection of the faintest stellar sources and instrinsic features, and detailed quantitative analysis of relatively bright sources. The development of such a telescope thus plays to the strengths of high time resolution (HTR) detectors which provide single photon detection capabilities and/or extremely high refresh rates—they can maximize detection of faint sources through photon counting and they can cope with the high photon flux from relatively bright objects building up extremely high S/N. Specific considerations and fast detectors then need to be adopted into the ELT design to accommodate high time resolution astrophysics (HTRA) efficiently. No one instrument or detector can cover all HTRA timescales (nanoseconds to seconds and ‘slower'), and a dedicated facility HTRA instrument on the ELT is unlikely as yet, but chosen facility instruments can include HTRA options in their packages. Currently there are numerous HTRA options in existing telescope facilities around the world as well as many visiting HTRA instruments. This demonstrates an active HTRA community with worldwide support and interest in HTRA observation capabilities, which underscores the need for HTR capabilities to be designed into the ELT. [ABSTRACT FROM AUTHOR]

Geiger-mode Avalanche Photodiodes (GM-APDs) are establishing themselves as potential candidates for the broad temporal range covered in high time resolution astrophysics (HTRA). These detectors have already been employed in astronomical instrumentation and significant results have been obtained to date. Their high time resolution and quantum efficiency make these single photon event counting detectors ideal for observations of stochastic phenomena, and ultimately for extreme HTRA observations. In this chapter, we review the technology and to illustrate their potential we briefly touch on specific science goals and astronomical applications. We then focus on the fabrication and characterisation of GM-APDs, and discuss the development and challenges posed in designing array devices. [ABSTRACT FROM AUTHOR]

Imaging detectors with high quantum efficiency over a wide spectral range, low noise, and fast readout will prove to be very useful in many applications in astronomy and other fields. In 2005 we have started to develop pnCCDs with high quantum efficiency for fast imaging of single optical photons in the wavelength range ∽350-1100 nm. The concept is based on fully depleted, back-illuminated pnCCDs with a sensitive thickness of 450 μmum which were originally developed for fast single photon X-ray imaging and spectroscopy. The pnCCD with column parallel readout shall be modified such that the on-chip JFET amplifiers are replaced by avalanche amplifier (AA) cells operated in the linear regime with a gain up to a few thousand. An additional on-chip n-channel MOSFET manages the suitable change of impedance such that the resulting signal can be handled by the following CAMEX readout ASICs. The amplification of the avalanche process must be sufficiently low to prevent optical crosstalk between the detector channels. The anticipated format in the imaging area will be of the order of 256× 256 pixels with a size of ∽50 μmum. The frame rate should be as high as 1000 frames per second. [ABSTRACT FROM AUTHOR]

We discuss the advantages and limitations of Electron Multiplying CCD technology in high precision photometry on short timescales, with special emphasis on probing the smallest structures in active galactic jets. Factors external to the EMCCD, rather than the architecture of the EMCCD itself, most often limit the precision of photometry that can be reached with groundbased observations. Although EMCCDs can be used in photon-counting mode, reliable photometry can still only be achieved when careful observing procedures are employed. Observations of a small sample of blazars taken with an EMCCD are briefly discussed. An innovative two-colour photometer, based on simultaneous observations with two EMCCDs is described and the science drivers are discussed. Novel opportunities for the use of EMCCDs in lucky photometry are outlined and it is clear that certain scientific questions cannot be addressed with groundbased observations taken with conventional CCDs. [ABSTRACT FROM AUTHOR]

Optical polarization is a valuable diagnostic tool in astrophysics, frequently enabling asymmetries in source regions, magnetic field configurations, and magnetic field strengths to be investigated. In the context of high time resolution astrophysics polarimetry is particularly valuable in understanding the nature of the optical pulsations from pulsars, and whilst the averaged (over many cycles) linear polarization of the Crab nebula pulsar was determined many years ago, no attempts have been made to determine the Stokes vector of single, individual, pulse cycles. This may be very important information in the investigation into the nature of the enhanced optical pulses associated with random giant radio pulses. In the case of the Crab nebula this requires an instrumental response time of no more than 100 μs, and, possibly, the capability of tagging individual photons with nanosecond resolution. This imposes certain constraints on the design of the polarimeter, which rules out all of the popular designs. We describe the design of a novel polarimeter which will be able to meet these constraints.This is based upon a design by Compain and Drevillon [1] in which their design is modified, by the use of a different glass and prism angles, to work over a wide bandwidth of 400-800 nm and with a high polarimetric efficiency. [ABSTRACT FROM AUTHOR]

Current astronomical instrumentation essentially exploits only spatial or temporal coherence properties of the incoming photon stream. However, beyond this first-order coherence, and encoded in the arrival times of the individual photons, information lies about the details of emission mechanisms such as stimulated emission or of subsequent scattering. The Extremely Large Telescopes of the future could provide the high photon flux needed to export to the astronomical field the photonic techniques currently applied in the laboratory. These ideas were developed in a conceptual study of a focal plane instrument (QuantEYE) for the 100 m OverWhelmingly Large Telescope of the European Southern Observatory. QuantEYE would be a novel astronomical photometer capable to push the time tagging capabilities toward the pico-second region. We are now building a prototype of QuantEYE for the Asiago 182 cm telescope (AquEYE), to be followed by a larger instrument for existing 8-10 m telescopes. This paper expounds the adopted technological solutions and the first steps performed to develop such a prototype [ABSTRACT FROM AUTHOR]

The HIgh-Time resolution (HIT) mode of FORS2 has 3 sub-modes that allow for imaging and spectroscopy over a range of timescales from milliseconds up to seconds. It is the only high time resolution spectroscopy mode available on an 8 m class telescope. In imaging mode, it can be used to measure the pulse of pulsars and spinning white dwarfs in a variety of high throughput broad- and narrow-band filters. In spectroscopy mode it can take up to 10 spectra per second using a novel "shift-and-wait" clocking pattern for the CCD. It takes advantage of the user-designed masks which can be inserted into FORS2 to allow any two targets within the 6.8' × 6.8' field of view of FORS2 to be selected. A number of integration, or more precisely ‘wait', times are available, which together with the high throughput GRISMs can observe the entire optical spectrum on a range of timescales. [ABSTRACT FROM AUTHOR]

A high-speed photo-polarimeter, "OPTIMA" short for Optical Pulsar Timing Analyzer, has been designed and developed in the group for gamma-ray astronomy of the Max-Planck-Institut für Extraterrestrische Physik. This sensitive, portable detector is used to observe optical emissions of sources that radiate mainly at X- and gamma-ray energies, like pulsars and other highly variable compact sources. The single photon counting instrument is based on fiber fed avalanche photodiodes (APDs), a GPS timing receiver,a CCD camera for target acquisition and a stand-alone data acquisition and control system. Several configurations are available: for photometry a hexagonal bundle with seven channels and one fiber offset for sky background monitoring; for polarimetry a rotating polarization filter in front of the photometer or a newly developed 4-channel double Wollaston system; and for coarse spectroscopy a 4-colour prism spectrograph. [ABSTRACT FROM AUTHOR]

Quantum optics potentially offers an information channel from the Universe beyond the established ones of imaging and spectroscopy. All existing cameras and all spectrometers measure aspects of the first-order spatial and/or temporal coherence of light. However, light has additional degrees of freedom, manifest in the statistics of photon arrival times, or in the amount of photon orbital angular momentum. Such quantum-optical measures may carry information on how the light was created at the source, and whether it reached the observer directly or via some intermediate process. Astronomical quantum optics may help to clarify emission processes in natural laser sources and in the environments of compact objects, while high-speed photon-counting with digital signal handling enables multi-element and long-baseline versions of the intensity interferometer. Time resolutions of nanoseconds are required, as are large photon fluxes, making photonic astronomy very timely in an era of large telescopes. [ABSTRACT FROM AUTHOR]

This chapter asks what high time resolution can bring to the study of stellar pulsation, with particular focus on the pulsations of subdwarf B stars. We give a brief introduction to the different types of pulsation found in stars, and identify which short-period oscillations might benefit from high-speed observations. We describe the basic properties of radial and non-radial oscillations, their effect on the stellar surface and emitted flux, and the consequences for the observer. The particular case of non-radial oscillations in subdwarf B stars and their potential for asteroseismology is outlined. Various campaigns to obtain high time resolution spectroscopy and photometry, and hence to identify pulsation modes in subdwarf B stars, are described in more detail. We close with a brief summary of problems in stellar pulsation likely to benefit from advances in high time resolution technology. [ABSTRACT FROM AUTHOR]

The large surveys and sensitive instruments of modern astronomy are turning ever more examples of variable objects, many of which are extending the parameter space to testing theories of stellar evolution and accretion. Future projects such as the Laser Interferometer Space Antenna (LISA) and the Large Synoptic Survey Telescope (LSST) will only add more challenging candidates to this list. Understanding such objects often requires fast spectroscopy, but the trend for ever larger detectors makes this difficult. In this contribution I outline the science made possible by high-speed spectroscopy, and consider how a combination of the well-known progress in computer technology combined with recent advances in CCD detectors may finally enable it to become a standard tool of astrophysics. [ABSTRACT FROM AUTHOR]

The discovery of pulsars in 1968 heralded an era where the temporal characteristics of optical detectors had to be reassessed. Up to this point detector integration times would normally be measured in minutes rather seconds and definitely not on sub-second time scales. At the start of the 21st century pulsar observations are still pushing the limits of detector/telescope capabilities. Flux variations on times scales less than 1 nsec have been observed during giant radio pulses. Pulsar studies over the next 10-20 years will require instruments with time resolutions below a microsecond, high-quantum quantum efficiency, reasonable energy resolution and sensitive to circular possible and linear polarisation of stochastic signals. This chapter is a review of temporally resolved optical observations of pulsars. It concludes with estimates of the observability of pulsars with both existing telescopes and into the ELT era. [ABSTRACT FROM AUTHOR]

Cataclysmic Variables (CVs) show a wide range of time-dependent phenomena which make them ideal objects of study with high time-resolution instruments. The most rapid timescales observed in CVs are of the order of a few seconds, and thus CVs are relatively slow objects compared to some phenomena studied by the high time-resolution community. However, the rich and varied processes which occur in CVs make high time-resolution observations powerful tests of cutting-edge astrophysics. Here we present a review of high time-resolution observations of CVs to date, and underline their relevance to modern astrophysics. [ABSTRACT FROM AUTHOR]

Geomagnetic indices play a significant role in describing the magnetic configuration of the Earth's magnetosphere. In the past 15 years, they have become a key parameter in Space Weather research, being commonly used to detect and describe Space Weather events. Research is currently being carried out into using them for forecasting. The objective of this paper is to contribute to a better understanding of the usefulness, potential and limitations of geomagnetic indices in Space Weather research and applications [ABSTRACT FROM AUTHOR]

The European Commission Directorate General Transport and Energy published in 2004 a summary report of research on aircrew dosimetry carried out by the EURADOS working group WG5 (European Radiation Dosimetry Group, http://www.eurados.org/). The aim of the EURADOS working group WG5 was to bring together, in particular from European research groups, the available, preferably published, experimental data and results of calculations, together with detailed descriptions of the methods of measurement and calculation. The purpose is to provide a dataset for all European Union Member States for the assessment of individual doses and/or to assess the validity of different approaches, and to provide an input to technical recommendations by the experts and the European Commission. Furthermore EURADOS (European Radiation Dosimetry Group, http://www.eurados.org/) started to coordinate research activities in model improvements for dose assessment of solar particle events. Preliminary results related to the European research project CONRAD (Coordinated Network for Radiation Dosimetry) on complex mixed radiation fields at workplaces are presented. The major aim of this work is the validation of models for dose assessment of solar particle events, using data from neutron ground level monitors, in-flight measurement results obtained during a solar particle event and proton satellite data. The radiation protection quantity of interest is effective dose, E (ISO), but the comparison of measurement results obtained by different methods or groups, and comparison of measurement results and the results of calculations, is done in terms of the operational quantity ambient dose equivalent, H* (10). This paper gives an overview of aircrew radiation exposure measurements during quiet and solar storm conditions and focuses on dose results using the EURADOS In-Flight Radiation Data Base and published data on solar particle events [ABSTRACT FROM AUTHOR]

The harsh radiation environment in the inner magnetosphere up to geosynchronous orbit is of major concern to an ever increasing amount of space hardware. While the average or quiescent conditions of the energetic particle population are fairly well characterized, the dynamics during magnetic storms are severely under-sampled. The description of the energetic electron and proton radiation environment at all points in space, which can provide reliable environmental data for locations of satellites that do not carry any energetic particle instrumentation is not trivial. The following approaches, theoretical, empirical, and model/data assimilation are examined in this paper [ABSTRACT FROM AUTHOR]

The solar wind effects on Earth environment are studied for their basic science value as well as for their crucial practical impact on human technological systems. Increased dissipation of solar wind energy in the near-Earth environment is a significant source of consequent perturbations in the upper atmosphere and ionosphere. This chapter addresses the ionospheric manifestation of geomagnetic storms induced by solar wind. Changes in the electron density distribution at the ionospheric F region heights above Europe during strong-to-severe geomagnetic storms, which occurred over present solar cycle, have been analysed. As for the seasonal preference, during storm main phase only negative phases dominate in summer, while during winter occurrence of both negative and positive phases is probable. Enhancements of electron density have been sometimes observed several hours before the onset of geomagnetic storm. Also the existence of few-hours-long periods during storm main phase, when the deviation of the electron density from median was insignificant, has been observed. Independent of the sign of the storm effect on F2 region ionisation, the effect on electron density at the F1 region heights at European higher middle latitudes has been found negative, if any at all. The F1 region response to magnetic disturbances also shows substantial summer/winter asymmetry. The stormy high latitude F region is most variable compared with middle and lower middle latitudes, being strongly influenced by magnetospheric processes, in particular, strong electric fields, which are usually present during geomagnetic storms. Several specific features of the storm-time high latitude ionosphere will briefly be mentioned including behaviour of ionospheric scintillations. The comparative analysis illustrates that the improved IRI-2001 model with the activated STORM option provides better description of the ionisation distribution above Europe under geomagnetic storm conditions. Nevertheless, our results show that model not always estimates correctly the storm phase and the magnitude of the effects on F region electron density [ABSTRACT FROM AUTHOR]

An analysis of the F2-layer short-term forecast problem has been done. Both objective and methodological problems prevent us from a deliberate F2-layer forecast issuing at present. An empirical approach based on statistical methods may be recommended for practical use. A forecast method based on a new aeronomic index (a proxy) AI has been proposed and tested over selected 64 severe storm events. The method provides an acceptable prediction accuracy both for strongly disturbed and quiet conditions. The problems with the prediction of the F2-layer quiet-time disturbances as well as some other unsolved problems are discussed [ABSTRACT FROM AUTHOR]

Global Navigation Satellite Systems (GNSS) are widely used to measure positions with accuracies ranging from a few mm to about 20 m. The effect of the Earth ionosphere on GNSS signal propagation is one of the main error sources which limits the accuracy and the reliability of GNSS applications. In particular, disturbed Space Weather conditions can be the origin of strong variability in the ionosphere Total Electron Content (TEC) which itself degrades the accuracy of GNSS applications. Space Weather effects on GNSS depend very much on the type of application. In this paper, we discuss the effects of Space Weather conditions on differential positioning with the Differential GPS (DGPS) technique and on relative positioning with the Real Time Kinematic (RTK) technique. We show that DGPS is affected by medium to large-scale gradients in TEC mainly observed at solar maximum when RTK will be degraded by smaller-scale ionospheric variability due to scintillations, TEC noise-like behaviour and Travelling Ionospheric Disturbances [ABSTRACT FROM AUTHOR]

Thermospheric density models are a main source of error in the orbit determination and prediction of low Earth satellites. The empirical models that are in wide use today show large systematic errors when compared with data derived from accelerometers and spacecraft tracking. This accuracy limit is inherent in their model formulation, which is based on an imperfect correlation of observed thermosphere density with a limited set of certain space weather proxy indices. It has been demonstrated that a substantially higher accuracy can be reached by model calibration using concurrent observations of satellite drag. Such drag observations can be obtained by processing freely available Two-Line Element (TLE) data, which are used for representing and distributing satellite orbit trajectories. Several aspects of this data processing require specific attention. These include the selection of suitable space objects, determining their ballistic coefficients, and taking into account thermospheric winds and radiation pressure accelerations [ABSTRACT FROM AUTHOR]

As a consequence of alterations of atmospheric chemical composition due to anthropogenic emissions, Earth's ionosphere and thermosphere are expected to change. A number of authors tried to detect signs of global change in their ionospheric data, but many findings remain controversial. We briefly review long-term trends observed in the critical frequencies of the ionospheric E and F2 layers as well as in the height of the F2-peak, i.e. the layer of maximum electron density. Using 48 years of F2-layer critical frequency data from Sodankylä, Finland, we demonstrate how the sign and amplitude of the detected trends depend upon the choice of model fitted to the data and suggest a method to choose the best possible model [ABSTRACT FROM AUTHOR]

In order to determine the influence of mankind on climate change it is important to understand the natural causes of climate variability. A natural effect that has been hard to understand physically is an apparent link between climate and solar activity. From historical and geological records there are strong indications that the sun has played an important role in the past climate of the Earth, but the physical mechanism is currently unknown. Whatever mechanism caused those earlier changes would most likely also be operating today and may have been active throughout the history of our planet. There have been several attempts to explain the link between solar activity and climate from variations in the sun's radiative output. These have tended to rely on simulations involving Global Climate Models (GCM), which are limited by our current understanding of the fundamental physics. In the following contribution, an outline of the current candidate mechanisms involving solar activity will be presented together with a description of the ESA funded project to study the Influence of Solar Activity cycles on Earth's Climate (ISAC) [ABSTRACT FROM AUTHOR]

Solar radiation is the fundamental energy source for the atmosphere and the global average equilibrium temperature of the Earth is determined by a balance between the energy acquired by the solar radiation absorbed and the energy lost to space by the emission of heat radiation. The interaction of this radiation with the climate system is complex but it is clear that any change in total solar irradiance (TSI) has the potential to influence climate. In the past, although many papers were written on relationships between sunspot numbers and the weather, the topic of solar influences on climate was often disregarded by meteorologists. This was due to a combination of factors of which the key was the lack of any robust measurements indicating that solar radiation did indeed vary. There was also mistrust of the statistical validity of the evidence and, importantly, no established scientific mechanisms whereby the apparent changes in the Sun might induce detectable signals near the Earth's surface. Another influence was a desire by the meteorological profession to distance itself from the Astrometeorology movement popular in the 19th century (anderson1999). Nowadays, with improved measurements of solar and climate parameters, evidence for an influence of solar variability on the climate of the lower atmosphere has emerged from the noise. This article provides a brief review of the observational evidence and an outline of the mechanisms whereby rather small changes in solar radiation may induce detectable signals near the Earth's surface is not possible to review here all potential mechanisms for solar-climate links. What is presented offers, necessarily, a personal perspective but, of the areas that are not covered, two may be pertinent: the effects of solar energetic particles on stratospheric composition (see e.g. jackman et al. 2005) and the possible influence of galactic cosmic rays on clouds through ionisation processes (see Marsh, this volume). [ABSTRACT FROM AUTHOR]

A factor for understanding the origin and evolution of life on Earth is the evolution of the Sun itself, especially the evolution of space climate and weather. Many aspects of the Sun's history remain to be understood. We reconsider constraints that knowledge of our own star implies for the emergence of life on Earth. This provides further insights into what may happen in other solar systems. Fortunately, particles emitted by the Sun in the past have left a record in geologic samples, but on this bases we cannot exclude earlier dates for the onset of life on Earth. A very early origin of life has to take into account the imprints of solar energetic particles during the first billion years (Gyr) after the formation of the Sun, approximately from 4.6 till 3.6 Gyr before the present (BP). Our review includes the isotopic fractionation of the noble gases, the depletion of volatile elements on the Moon and constraints for the origin of life on Europa, the icy moon of Jupiter [ABSTRACT FROM AUTHOR]

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Solar energetic particles (SEPs) in the interplanetary (IP) medium are transported under the influence of electromagnetic fields of the solar wind. These fields consists of the smooth background fields, which can be modeled by the MHD equations governing the expansion of the solar wind, and of the small-scale fluctuations (waves or turbulence) that scatter the particles in pitch angle and act as agents enabling their acceleration at IP shock waves. We review theoretical models of SEP transport and acceleration in the IP medium. We start from the simple analytical approaches (diffusion models), which assume quasi-isotropic particle distributions, and then continue to the more accurate numerical approaches based on the focused transport equation, not making this simplifying assumption. A careful analysis of two SEP events, an impulsive and a gradual one, is presented and the spatial scaling of their peak intensities, differential fluences and time-integrated net fluxes is discussed. We conclude that rather simple scaling laws for these quantities can be obtained for impulsive events but no simple scaling laws can be expected to govern the gradual SEP events [ABSTRACT FROM AUTHOR]

In this interview, Émile Schweitzer recalls the history and the current activities of the “Association Française des Observateurs d’Étoiles Variables” (AFOEV) [French Association of Variable-Star Observers] that started in 1921 to collect magnitude estimates from observers in France and abroad. The data, entirely published, are put - free of charge and without prior request — at the disposal of professional astronomers using them and proposing collaborative programs to the members of the association. [ABSTRACT FROM AUTHOR]

Journalists writing about astronomy bring varying levels of knowledge to the task. Most rely on astronomers for help. To be most helpful, astronomers should familiarize themselves with the practices and needs of journalists and learn effective methods for presenting astronomy via news releases, interviews and news conferences. In all aspects of communicating with the media, the ability to express technical findings in plain language is essential. [ABSTRACT FROM AUTHOR]

The authors describe the various outreach activities at Jodrell Bank Observatory: Visitor Centre (new one being designed), web site, distance learning, school programmes, work with astronomical societies and with other community groups, and finally, interactions with the national and local media. [ABSTRACT FROM AUTHOR]

Hands-On Universe (HOU) is a slowly but steadily growing international endeavor that teaches students and teachers modern astronomy through the acquisition, measurement, and analysis of real images from either the International Virtual Observatory or a developing network of small robotic telescopes. This intrinsically global effort shares data, teachers, scientists, students, telescope sites, lesson plans, teacher training strategies, software, collaborative tools, and other resources. Such resources can be spread both ubiquitously and effectively through modern web-based technologies and traditional means. Astronomy has proven to be a superb mechanism to engender and support worldwide collaboration and cooperation; global HOU currently has embraced collaborators from six continents, and is endeavoring to build telescope resources in Antarctica. HOUer’s want to work together and find more and more reasons — as the technology becomes congruent — to be optimistic about the future. An underlying raison d’être of HOU is that students can effectively learn science by actually doing science in “real-world” situations — skills of data analysis, experiment planning, collaboration and cooperation. Such skills are necessary for the future well being of students all over the world. [ABSTRACT FROM AUTHOR]

This article describes the International Planetarium Society, presents a brief history of the organization, discusses its structure, elucidates some challenges it faces and changes it may undertake over the next few years, and examines those issues in light of the changing nature of planetariums and the astronomy materials they present to their audiences. [ABSTRACT FROM AUTHOR]

This chapter recalls the history of the first European astronomy magazine in French, Ciel & Espace. The way it is currently produced is described, as well as the problematics of information sources. An account of the Nuit des Étoiles [Star Nights] is also given. [ABSTRACT FROM AUTHOR]

A few highlights in the history of Near-Earth Object research are outlined along with early, relevant IAU activities. The development of an IAU policy on this research and its implementation in relation to international organizations like the United Nations is described. Special attention is paid to the rôle of the IAU Minor Planet Center and how the IAU has dealt with related problems. An important issue, often causing controversy, has been the need to communicate findings on asteroidal motions that may lead to impact on the Earth within the next century. An account is given of the IAU’s involvement in this issue with the aid of several examples of noteworthy cases. Finally, recent activities aiming at a multidisciplinary scientific assessment of the impact hazard, involving the International Council for Science, is presented. [ABSTRACT FROM AUTHOR]

Since 1995, more than 140 planets around solar-type stars have been discovered. The great success of the first decade of observational research in exoplanets, where both the number of planets detected and the number of research groups in the field have grown in parallel, will be followed by a golden age in exoplanet discovery. In the next 15 years, current and planned searches with observatories in space and on the ground will increase this number by at least two orders of magnitude unveiling the distribution of masses, periods and eccentricities of exoplanetary systems. We will possibly see the discovery of Earth-like planets around other stars and major efforts will be conducted to detect signatures of biological activity in their spectra. [ABSTRACT FROM AUTHOR]

This chapter examines the salient characteristics of Space Law. It analyzes the origins and evolution of Space Law, its main international principles, and some current topics of interest to the scientific community: the delimitation of airspace and outer space, intellectual property, and criminal responsibility. [ABSTRACT FROM AUTHOR]