[en] It seemed appropriate to devote the 1980 School to the origin of the solar system and more particularly to the formation of planetary systems (dynamic accretion processes, small bodies, planetary rings, etc...) and to the physics and chemistry of planetary interiors, surface and atmospheres (physical and chemical constraints associated with their formation). This Summer School enabled both young researchers and hard-nosed scientists, gathered together in idyllic surroundings, to hold numerous discussions, to lay the foundations for future cooperation, to acquire an excellent basic understanding, and to make many useful contacts. This volume reflects the lectures and presentations that were delivered in this Summer School setting. It is aimed at both advanced students and research workers wishing to specialize in planetology. Every effort has been made to give an overview of the basic knowledge required in order to gain a better understanding of the origin of the solar system. Each article has been revised by one or two referees whom I would like to thank for their assistance. Between the end of the School in August 1980 and the publication of this volume in 1982, the Voyager probes have returned a wealth of useful information. Some preliminary results have been included for completeness

[en] In this paper, description of a complete theory of the formation of planetesimals is not ambitioned, but that simple arguments can give some hints on the initial conditions in the solar nebula is showed. Some idea on time scales and processes is tried to be got from the mass of the actual planets as the only data. Computations will be in order of magnitude only, numerical multipliers of order I will generally be omitted. Many important effects will be omitted. Some ideas on the properties of the protoplanetary disc are wanted and what could be a good starting point is to find out

[en] This series of lectures will review the physical and chemical characteristics of the objects we find in the solar system today with the goal of trying to identify features that can be used to shed some light on the processes involved in the origin and evolution of the entire system

[en] In this paper, we restrict ourselves to the description of those results most relevant to the problems of the formation and early evolution of the Moon: internal structure, bulk chemical composition and chronology of the major events. The major models proposed for the origin of the Earth-Moon system are then presented: fission, capture, and accretion in orbit. They are confronted with the new available experimental data, so as to assess the present status of the problem. Finally, studies further needed to discriminate unambiguously between the various models are tentatively outlined

[en] Phobos and Deimos appearance is described. Some results of Viking flybys are discussed

[en] Before attempting to describe a possible scenario for the formation of the Solar System we need to go backward in time to ascertain the state of the planetary system shortly after its formation. Such an endeavour is far too ambitious to be fully completed with confidence given our current knowledge of the dynamical or chemical processes that have been at work for several billions years. As an example of this kind of investigation the orbital history of Phobos and Deimos can be studied by means of an easy-to-describe model of tidal interaction and allows to put some constaints on their initial orbits

[en] Practically everything we know about the atmosphere of Venus is derived from data acquired at the same time in December 1978 by the simultaneous missions Venera 10 and 11 and Pioneer Venus. Composition of the lower atmosphere is given. The atmosphere structure is described in three main regions: troposphere, mesosphere and thermosphere. The clouds of Venus are described in detail, composition, size of the particles responsible of the clouds, morphology are given. The radiative properties are listed. The dynamics of the Venus atmosphere is discussed which leads to their evolution in time

[en] The question why to measure the hydrogen to helium ratio on Jupiter and Saturn is answered and consequences are recalled. After differents methods to determine this ratio in the grant planets have been listed, the data from Voyager in Jupiter and Saturn are presented and discussed

[en] These lectures concentrate on the physics and chemistry of the nucleation and growth of grains. The general theory of grain nucleation is explored, and an approximate analytical treatment is developed. The latter is applied to several astrophysical environments, such as novae, supernovae, red giants, planetary nebulae and the proto-solar nebula. The calculation of chemical equilibrium and disequilibrium condensation is explored and applied to the origin of meteorites, especially with regard to the question of isotopic anomalies. The relation of these problems to the origin of the solar system is discussed

[en] Carbonaceous chondrites (CC) constitute the most primitive solar system matter available on Earth. Over the past decade, the improvement in our understanding or these processes has been tremendous. It proceeded through detailed characterisations of CC, using sophisticated analytical techniques. In particular, mineral phase extracted from several CC exhibit very peculiar isotopic compositions likely to originate from the admixture in varying proportion of isotopes formed in specific presolar nucleosynthetic sites. These ''isotopic anomalies'' would then constitute direct signatures of the stellar and interstellar environment of the protosolar nebula. In this paper, we briefly present and discuss the major experimental steps which have drastically modified the models accounting for the early history of the solar system. Tentative conclusions concerning the existence of unaltered presolar grains in meteorites are proposed