The formation of the solar system
Résumé
The solar system started to form about 4.56 Gyr ago and despite the long intervening time span,
there still exist several clues about its formation. The three major sources for this information are
meteorites, the present solar system structure and the planet-forming systems around young stars.
In this introduction we give an overview of the current understanding of the solar system
formation from all these different research fields. This includes the question of the lifetime of the
solar protoplanetary disc, the different stages of planet formation, their duration, and their
relative importance. We consider whether meteorite evidence and observations of protoplanetary
discs point in the same direction. This will tell us whether our solar system had a typical
formation history or an exceptional one. There are also many indications that the solar system
formed as part of a star cluster. Here we examine the types of cluster the Sun could have formed
in, especially whether its stellar density was at any stage high enough to influence the properties
of today’s solar system. The likelihood of identifying siblings of the Sun is discussed. Finally,
the possible dynamical evolution of the solar system since its formation and its future are
considered.