Solar System

What is the Solar System?

The Solar System consists of the Sun, eight official planets, atleast 130 natural satellites of the planets and a large number of small bodies (comets, asteroids & meteors).

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%
Interplanetary Medium       0.0000001%




The official planets of the Solar System include:-

- Mercury
- Venus
- Earth
- Mars
- Jupiter
- Saturn
- Uranus
- Neptune
                                                                                                                                                                                                                             Spiral Galaxy

How did the Solar System evolve?

Our Solar System began evolving in a huge cloud of hydrogen gas and dust nearly 4600 million years ago. This cloud of gas and dust was known as the Solar Nebula. Under the influence of its own gravity, the Nebula collapsed into a disk and the Sun was formed at its centre. The Sun slowly started absorbing the dust & gas components of the Nebula.


Inside the Solar Nebula, dust & ice particles usually collided and merged with each other, thereby forming bigger bodies that were up to a few kilometers across.

The inner portion of the Nebula was very hot and bodies close to it had a high concentration of metals. The cooler outer portion of the Nebula consisted of bodies with a high concentration of water ice & gases in their composition.

The bodies formed as a result of continuous collisions, were now big enough to have their own gravitational pull. This increased the frequency of collision between the bodies and the bigger bodies grew much faster. As a result, four big planets namely Mercury, Venus, Earth and Mars were formed. In the inner portion of the Nebula, the gravitational pull of the Sun was very strong and therefore the planets formed were much nearer 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 were formed.

The Sun absorbed much of the gas & dust of the Solar Nebula and the rest were taken in the planets, thus giving birth to our Solar System.