I think you mean "protoplanet hypothesis".
In fact, astronomers usually call it the Nebular Hypothesis
A protoplanet is a planet-like object that hasn't fully developed into a planet.
Why that hypothesis?
It's because it is the best we have to describe the origin of the solar system according to the Laws of Physics.
Extra debris was swept out away from our solar system by the sun's radiation and solar wind towards the end of the formation of our solar system.
gigiity
What begins the process of solar system formation? Gas and dust in a nebula is disturbed by an outside force. Apex
The first stage of the formation was the elipse there is a solar elipse its really cool :)
It shows that we do not fully understand the formation of our Solar System.
The formation of sun is the most important part of solar system formation. Sun is the reason for formation of rocky planets.
Extra debris was swept out away from our solar system by the sun's radiation and solar wind towards the end of the formation of our solar system.
the solar role
gigiity
Most object that are currently in the Solar System are such remnants.
star formation and protoplanitery disks the solar system formed 4.5-4.6 billions ago
Some rocks are younger then the formation of the solar system because of changes caused by volcanic activity
What begins the process of solar system formation? Gas and dust in a nebula is disturbed by an outside force. Apex
Life?
the solar system
The first stage of the formation was the elipse there is a solar elipse its really cool :)
Kuiper Belt objects