How were the planets of the solar system formed
The planets of the solar system were formed approximately 4.6 billion years ago through a process called accretion. The formation of planets began with a giant molecular cloud composed mostly of hydrogen and helium, along with trace amounts of other elements. This cloud started to collapse under its own gravity, which led to the formation of a spinning disk known as the protoplanetary disk or the solar nebula.
Within this disk, matter started to clump together due to gravity and form small objects called planetesimals. These planetesimals were made up of rock, dust, ice, and gas. Over time, these planetesimals collided and merged with each other, gradually growing in size. The accumulation of these collisions resulted in the formation of protoplanets.
These protoplanets continued to grow and eventually reached a mass where their gravitational pull started to clear their surrounding orbits. This process is known as planetary accretion. The protoplanets swept up the remaining gas and dust in their vicinity, further increasing their size.
As the protoplanets continued to accrete material, they started to differentiate, with heavier elements sinking to the core while lighter materials remained on the surface. This differentiation process led to the formation of terrestrial planets like Earth, which have a solid, rocky composition, and gas giants like Jupiter and Saturn, which have a gaseous atmosphere.
The formation of the planets was a complex and gradual process that took millions of years. The final positions and characteristics of each planet were influenced by factors like their distance from the Sun, the composition of the protoplanetary disk, and gravitational interactions between neighboring bodies.