Solar System is a star system consisting of: Sol Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Along with The Asteroid Belt between Mars and Jupiter, and The Kuiper belt, Oort cloud, and other Trans-Neptune objects. All of which are celestial bodies bound to The Sun by gravity, which formed from the collapse of a giant molecular cloud approximately 4.6 billion years ago. The Sun's retinue of objects circle it in a nearly flat disc called the ecliptic plane, most of the mass of which is contained within eight relatively solitary planets whose orbits are almost circular. The four smaller inner planets; Mercury, Venus, Earth and Mars, also called the terrestrial planets, are primarily composed of rock and metal. The four outer planets, Jupiter, Saturn, Uranus and Neptune, also called the gas giants, are composed largely of hydrogen and helium and are far more massive than the terrestrials.
The Solar System is also home to two main belts of small bodies. The asteroid belt, which lies between Mars and Jupiter, is a belt consisting of Asteroids, and a dwarf planet. The asteroid belt might be the rests of the creation of the Solar System, or might have been a planet in the beginning that was destroyed, which can explain all the numerous impact craters on Mars, its closest terrestrial planet neighbour. The Kuiper belt (and its subpopulation, the scattered disc), which lies beyond Neptune's orbit, is composed mostly of ices such as water, ammonia and methane. Within these belts, five individual objects, Ceres, Pluto, Haumea, Makemake and Eris, are recognised to be large enough to have been rounded by their own gravity, and are thus termed dwarf planets. The hypothetical Oort cloud, which acts as the source for long-period comets, may also exist at a distance roughly a thousand times beyond these regions.
Within the Solar System, various populations of small bodies, such as comets, centaurs and interplanetary dust, freely travel between these regions, while the solar wind, a flow of plasma from the Sun, creates a bubble in the interstellar medium known as the heliosphere, which extends out to the edge of the scattered disc.
Six of the planets and three of the dwarf planets are orbited by natural satellites, usually termed "moons" after Earth's Moon. Each of the outer planets is encircled by planetary rings of dust and other particles.