O Solar system it's the set constituted by the Sun (which is at the heart of the system) and by a large number of others celestial bodies that revolve around it and are held together as a physical unit by gravitational attraction.
The orbiting bodies comprise the eight main planets (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Neptune, Uranus), their satellites, the dwarf planets (Pluto, Eris, Ceres, Makemake and Haumea), thousands of asteroids, whose orbits lie mainly between those of Mars and Jupiter, and an immense number of comets and meteoroids. The Sun contains 99.86% of the entire mass of the system, while most of the remaining mass is concentrated in Jupiter.
Until 2006, Pluto was recognized as one of the main planets in the Solar System. However, after the discovery of several celestial bodies of similar size (and some even larger than Pluto) in the Belt of Kuiper, the International Astronomical Union (U.A.I.) decided, on August 24, 2006, to classify Pluto as a planet dwarf.
The shape of the solar system can be considered spherical, and the age of the solar system is in the order of 4.6 billion years. There are several theories about its origin, but the most widely accepted is the modern version of the Laplace protosolar nebula, according to which the solar system arose from the fragmentation of a rotating gas disk, which had formed by contraction of a gas cloud. interstellar. Studying the composition of meteorites suggests that the formation of the solar system was associated with the explosion of a supernova; after the explosion, matter, with a peculiar chemical composition, was launched at great speed, in all directions, colliding with the primitive nebula, which was forced to contract beyond the point where it is no longer possible to counteract the gravitational forces. As a result of this contraction, the primitive nebula broke up and caused the formation of the solar system.
