The solar system’s formation began 4.5 billion years ago. A planetary nebula is the base within which the solar system is formed. Planets, the sun and various smaller entities develop out of this system comprised of heavy masses of cloud, dust and gas. As the nebula's particles group together the system condenses...
The sun becomes nebula's nucleus and makes up 98% of the solar system’s mass. Planets will develop around this entity. These are smaller composites of matter which will form an orbit as they condense and become compressed against one another over time by gravity.
Like the sun, the planets expand in size by drawing in smaller particles over millions of years. Moons are yet smaller entities which develop as the planet's natural satellites . Moons orbit around planets as they become locked in their gravitational pull. Meteors, comets and asteroids are among the smallest particles which subsist in a solar system. These have no orbital alignment. The solar system continuously evolves.
Although it is often hard to relativise it's evolving dynamics considering its age...
and the billions of years it still has before it.