The tradition of astronomy in Europe has been unbroken from the Neolithic and Bronze Age menhir monuments of north-western Europe to its large telescopes and space-probes. While astronomy still retains practical features, in most part it now concentrates on discovering new science. Recent advances include the discovery of previously unsuspected properties of neutrinos, confirmation of the theory of general relativity near black holes and the successful development of a coherent theory of the origin of the Universe in the Big Bang. These discoveries suggest that 19/20ths of the density of the Universe is of unknown form. There is more to do!

Astronomers have built the main components of a scenario for the formation of the Solar System. Small planetary bodies accreted others by collisions within a rotating protoplanetary disk that formed at the same time as the Sun. While terrestrial planets near the warming Sun could accumulate only solid metallic and silicate material, the giant planets formed from ice and gas at lower temperatures. Each planet and satellite then followed its own specific evolution, depending upon the properties of its atmosphere and/or surface. Information about the origin and evolution of the Solar System is also provided by the comets, which can be considered as frozen fossils of the Solar System's early stages. On the borders of the outer Solar System, beyond the orbit of Neptune, the newly discovered Edgeworth–Kuiper belt is probably the reservoir where short-period comets are formed.

The discoveries of the first planets around a pulsar and around a star similar to our Sun have opened, after centuries of speculation, a new era in astronomy. The quest for other worlds has become reality. In this paper, the motivations for this search are presented. A comparative review is made of different techniques for their detection, with special attention paid to the planet parameters that can be derived from each method. The first discoveries and their astrophysical consequences are analysed. New questions and future projects beyond these first discoveries are reviewed, with special attention given to the search for life in extrasolar planetary systems. Finally, worldwide activities and the role of Europe are described.

For 200 years, black holes have been a solution looking for a problem. In the last two decades they have moved to become a real scientific phenomenon. Black holes exist both as stars in our own Galaxy (identifiable as members of binary stars that emit X-rays) and as the centres of energetic galaxies (‘active galactic nuclei’). The last decade has seen the first accurate mass measurements of these black holes, which lie in the range from five times the mass of our own Sun to many million times. We also have clear evidence for the way that black holes accrete material as their primary energy source. Furthermore, the presence of super-massive black holes has been established in some nearby galaxies, and in the centre of our own Galaxy, from their gravitational effect on nearby stars. Some observations show processes that occur very close to the black hole, where the field of gravity is strong enough to test General Relativity. Recent observations suggest the existence of intermediate mass black holes of an as yet unknown origin.

The 20th century saw the establishment of the first quantitative theory seeking to describe the behaviour of the Universe as a whole – the Big Bang. This sets up a framework within which there has been great success in interpreting a wide range of observations, including the abundances of light chemical elements, the existence and spectrum of the cosmic microwave radiation, and the formation and evolution of galaxies. At the end of the 20th century, the surprising conclusion of the Big Bang theory is that 95% of the Universe is made of two different unknown types of material whose nature remains unclear: dark matter and dark energy. Needless to say, this is a major challenge for science. At the beginning of the 21st century, cosmology appears poised to enter a high-precision era, where the key quantities of cosmology will be determined to two or more significant figures. If cosmologists are on the right track, this will confirm the existence of dark matter and dark energy; if not, it will force us to revise our current picture of the Universe. Either way, the prospect is for exciting years ahead in cosmology.

The Big Bang created primordial material from which the first stars formed. These stars exploded as supernovae and polluted the material from which subsequent generations of stars were made. Astronomers have had difficulty in finding stars made of the pure Big Bang material, but they have found stars with very little polluting material. The age of these cosmological relics of the first eras sets a lower limit for the age of the Universe we live in. European astronomers and their colleagues worldwide have joined in the effort to discover and date these, the oldest stars, and cast a glance into the obscure phases between the very first seconds of the existence of the Universe and the epoch at which galaxies and clusters of stars matured. Many independent techniques have been devised to date the oldest stars and stellar systems in the Universe. Some of them are briefly reviewed. The age of the oldest stars is now converging on a value in the range from 12 to 15 thousand million years. However, a large uncertainty still exists and a value as a large as 17 to18 thousand million years cannot be totally ruled out. Such a large value would be difficult to reconcile with the age of the Universe based on cosmological data. Significant improvements in the uncertainties of this situation are expected from the 8–1 m telescopes and space missions of the next decade.

Space weather is caused by conditions on the Sun and in the solar wind, the magnetosphere, ionosphere and thermosphere that can influence the performance and reliability of space-borne and ground-based technological systems and can affect human life or health. It affects man-made systems such as satellite electronics, terrestrial power grids and radio communications. This paper provides an overview of how space weather arises in the solar–terrestrial system and how physical processes are able to cause space weather effects. We also discuss European perspectives and activities geared towards the possible initiation of a European Space Weather programme.

For some decades, astronomy and astrophysics have undergone a technological and conceptual revolution. Supported by ever more powerful telescopes and instruments on the ground and in space, the volume and quality of new insights is incredible, both in terms of physical understanding of individual celestial objects and the grand evolutionary scheme. New and powerful observational facilities such as the ESO Very Large Telescope (VLT) are opening new horizons, from the nearby solar system to the corners of the Milky Way galaxy in which we live and, not least, towards the vast expanses in time and space of the remote and early Universe. The next generation of ultra-sensitive optical-infrared telescopes such as Herschel and ALMA will be ready within this decade and concepts are being elaborated for the construction of super-giant telescopes like the 100 m optical/IR OWL, the ‘Overwhelmingly Large telescope’. With these impressive developments, and in a true spirit of exploration, astronomers can now look forward to great research opportunities, in a resounding manifestation of the continuous drive towards a better understanding of our cosmic surroundings and of our own origins, so characteristic for enlightened humankind of every age.

The special value of radio astronomy lies in the probing of extreme conditions in the universe, including the highest energies and the lowest temperatures. Radio waves can penetrate clouds of gas and dust to reveal objects in the universe and, in particular, in our Galaxy that cannot be seen by visible light. To achieve the highest resolution, radio telescopes in widely separate parts of our globe combine their reception to produce a synthesized image. This is a splendid example of international collaboration. Among the images visualized are pulsars, derived from the remnants of supernovae explosions, and quasar sources powered by black holes.