Our solar system consists of one major star, i.e. the Sun, with 8 planets revolving around it and at least 130 natural satellites of the planets along with a large number of small space bodies like comets, asteroids & meteors, revolving around these planets. According to the scientists our solar System was born about4.6 billion years ago. It was not something like the "Big Bang" and all the planets slowly evolved with time, it took billion of years to do that.
The presence of dust, gases and parts of other planets and stars formed our solar system. With the birth of the Sun, the same process created the planets revolving around it as the asteroid belts developed. The sun , the planets, the moons and other celestial bodies that move around the sun make up the solar system.
The Earth along with seven other planets move around the sun. Apart from the planets, celestial bodies like dwarf planets, asteroids, comets and meteoroids move around the sun. Some planets and other celestial bodies have moons or satellites, moving around them. Moons also moves around the Sun as the planets go around the sun.
The total mass distribution of the Solar System is as follows:
- Sun 99.85%
- Planets 0.135%
- Comets 0.01%
- Satellites 0.00005%
- Minor Planets 0.0000002%
- Meteoroids 0.0000001%
- Medium 0.0000001%
The solar system is made up of two parts:
- The inner solar system: Mercury, Venus, Earth and Mars. These four planets are closest to the Sun
- The outer solar system: Jupiter, Saturn, Uranus, Neptune and Pluto
- The Asteroid Belt separates the inner planets from the outer planets.
Rocky Planets (Mercury - Venus - Earth - Mars - Pluto)
The rocky planets are mainly made up of rock and metal. These planets are very heavy and and they move very slowly. They do not have rings and very few moons.
Gas Planets (Jupiter - Saturn - Uranus - Neptune)
The gas planets are mainly made up of gases (hydrogen and helium). These planets are light for their sizes (just like a big air balloon) and move quickly. They have rings and many moons.
How did the Solar System evolve?
According to the scientists about more than 4500 billion years ago our Solar System began evolving as a huge cloud of hydrogen gas and dust.
Our Solar System began evolving in a huge cloud of hydrogen gas and dust nearly 4600 millionyears ago. it was known as the solar Nebula, the cluster of cloud and dust. Under the influence of its own gravity, the Nebula collapsed into a disk and the Sun formed at its center. The Sun slowly started absorbing the dust and gas components of the Nebula.
Inside the Solar Nebula, the ice and dust particles started to collide and merge with each other, forming much bigger bodies which were few kilometers apart from each other. The core of Nebula was very hot and the near by bodies had a high concentration of metals. The outer regions were cooler and those bodies consisted mainly of icy water along with gases. As these bodies became larger in size, their individual gravitational pull increased, resulting to faster collision and thus the first four planets of Mercury, Venus, Earth and Mars were formed. Since the gravitational pull at the core of Nebula was very strong, these planets stayed close to the Sun.
In the outer portion of the Nebula, where the gravitational pull of the Sun was weak, big gas giants namely the Jupiter, Saturn, Uranus & Neptune formed.
The Sun absorbed much of the gas and dust of the Solar Nebula and the rest were taken in the planets, thus giving birth to our Solar System.
About 99.86percent of the mass of the Solar System is made up of the Sun