The solar system contains the planetary system and the Sun which orbits it directly or indirectly. Those objects which orbit the sun directly, the largest eight are the planets, the remaining being considerably smaller objects like dwarf planets and the smaller bodies of the solar system like asteroids and comets. In addition to planets, our solar system also has moons, dust and gas.
4.6 billion years ago, the solar system formed from the gravitational collapse of a huge interstellar molecular cloud. The huge majority of the system’s mass is in the Sun, and, most of the residual mass is contained in Jupiter. Venus, Mercury, Mars and Earth and the terrestrial planets are the four smaller inner planets, are mainly composed of metals and rocks. The four outer planets are huge planets and they are largely more enormous than the terrestrials. Saturn and Jupiter are the two largest planets and they are gas colossal. Mainly, they are composed of Helium and Hydrogen. Neptune and Uranus are the two outermost planets and they are the ice giants. Compared with Hydrogen and Helium, they are composed of substances with relatively high melting point, called ices, like ammonia, methane and water. Almost all the planets have circular orbits which lie in a flat disc known as ecliptic.
The Asteroid Belt
The solar system also has smaller objects. The asteroid belt lies between the orbits of Jupiter and Mars. Mostly, it contains objects which are composed like the terrestrial planets of metals and rocks. The Asteroid belt is made up of thousands of small objects. Further than the orbit of the small planet Pluto, there is another belt known as the Kuiper belt. The asteroid belt is also known as main belt or main asteroid belt. This belt comprises various unevenly shaped bodies known as minor bodies. The four largest asteroids, the Vesta, Ceres, Hygiea and Pallas, comprise about half the mass of the asteroid belt. The asteroid belt’s total mass is approximately 4% that that of the moon. The Ceres asteroid belt is a dwarf planet which is about 950 km in diameter, while, Hygiea, Pallas and Vesta have a diameter of less than 600 km. As a group of Planetesimals (object formed from dust, rock, and other materials.), the asteroid belt is formed from the primordial solar nebulae. Actually, Planetesimals are the smaller pioneers of the Protoplanets.
The solar wind and a stream of charged particles flows outwards from the sun, and in the interstellar medium, they create a bubble like region which is known as the heliosphere. The Heliopause is the outer boundary of the Heliosphere. The Heliopause is the point at which the solar wind stops and is the starting of interstellar space.
In the late middle ages, most people believed, Earth to be stationary at the center of the Universe. Johannes Kepler, Galileo Galilei and Isaac Newton discovered an understanding of Physics which led to the continuing acceptance that Earth moves around the sun and the planets are administered by the same physical rules which are administered by the Earth.