It is said that the solar system was formed approximately 4.6 billion years ago. At that time of origin the solar system was only a cloud of dust and gas known as a the solar nebula. It is believed that our Solar System was formed when a cloud of dust and gas was disturbed by an explosion of a nearby star called the Supernova.
According to the theory of explaining the origin of the solar system called the big bang theory, the star exploded with a Bang.
It resulted in the spreading of the dust of the cloud because of the collapse. All those small pieces of matter that started out running away from each other, got pulled back together by gravitational forces.
Gravity collapsed the material in on itself as it began to spin, then spinning slowed down, the center of the Solar Nebula became hotter and denser, which was surrounded by a disc of gas and dust that was cool at the edges.
There was a ball of Hydrogen gas whose pressure and temperature became quite huge and the particles began to fuse and formed our Sun in the center of the nebula.
Due to the rise of the sun, the remaining particle material began to clump together into larger collections. The small particles drew together, bound by the gravitational forces, into some larger particles. The solar wind swept away lighter elements, such as hydrogen (H) and helium (He). These light elements gave birth to gas giants. From the closer areas, leaving only the heavy, rocky materials in order to create the terrestrial worlds.
Therefore Planets can be categorized into three groups according to their formation.
Categorization of the planets
01. Terrestrial Planets – Planets that are composed of rocky materials and closed to the sun (Mercury, Venus, Earth, Mars)
02. Gas giants – Planets that are composed of gases and far away from the sun. Large in size (Jupiter, Saturn)
03. Ice giants – Planets that are mainly composed of dense gases which are heavier than those found in gas giants. (Neptune, Uranus)
In this way, The sun, asteroids, comets, planets, and moons were created.
Theories that explain the origin of the Solar system
The nebular theory is the first scientific explanation of the origin of the solar system.
According to this theory, small particles of materials in the universe drew together by the force of gravity, clumped up, and the galaxies, the sun, and the other planets were formed.
Big Bang theory
Big Bang theory can be considered as the modern theory about the origin of the Earth. According to this theory, the universe was an energy source with great energy. A significantly giant explosion took place in the universe and large clouds of dust particles were created as a result of the explosion. These dust particles that were formed, clumped up together and the end result was the creation of the galaxies. It is said in the big bang theory that our solar system was created in the galaxy known as the milky way galaxy.