Origin of the Solar System (английский)

 Three basic theories have been put forth to explain the creation of the universe (Fig. 1): the big bang theory, in which the universe keeps expanding; the steady state theory, in which the universe exists indef- initely; and the pulsation theory, in which the universe begins and ends repeatedly.According to the big bang theory discussed here, all matter in the universe, including a wide assortment of stars, galaxies, galaxy clusters, and superclusters, was created during a gigantic explosion around 15 billion years ago. Subsequently, every chemical element in the periodic table formed dur- ing little bangs by huge exploding stars called supernovas. Consequently, we are products of the universe. Every atom in our bodies and all the materials that make up Earth came from the stars. About two-thirds outward from the center of the Milky Way galaxy, which theoretically contains a black hole at its core—where matter and energy disappear as though down a cosmic drain pipe, lies a lone, ordinary star.That star happens to be our Sun (Fig. 2). Single,medium-sized stars, such as the Sun, are somewhat of a rarity in this galaxy.They are perhaps the only ones with orbiting planets.Thus, of the myriad of stars overhead, only a hand- ful possess planets, and fewer yet contain life.