How did the planets in the solar system form?

1 Answer
Nov 16, 2015

From a cloud of Dust and Gas.


All Planets in our Solar system were formed at the same time from a rotating cloud of dust and gas moving through interstellar space in the Milky way galaxy except Pluto which shows signs of having being captured. This cloud collapsed around 4.5 Billion years ago, mainly because of a gravitational event probably from a dying nearby star. When the cloud collapsed the temperature became hot enough to allow nuclear fusion as mostly all nebulae contain hydrogen, the fusion process turned it into Helium giving birth to our Sun.

In the beginning, the Sun also called a Proto-Sun was very much brighter and more Radiant then it is now. The protosun was able to give away enough radiation to drive away gas from the inner Solar system leaving behind the rocky cores known as the Terrestrial planets.

The Sun at that time too was not radiant enough to draw gas out of the Outer Solar system, so with the passage of time the rocky cores in the Outer Solar system were able to accumulate mantles of gas, making them gas Giants.

Pluto on the other hand shows signs of having being captured rather than forming at the same time with other planets.enter image source here