This mesmerizing video shows how incredibly vast space really is

[longship]

3. Preservation of angular momentum.

The cloud from which the solar system coalesced would have non-zero rotation. As it contracted, any rotation would increase, like ice skaters when they pull in their arms. The only stable orbits would be objects with the same orbital direction and mostly circular orbits in the plane of rotation. Roughly -- Pluto is significantly inclined to the ecliptic plane and is quite elliptical, Uranus rotates on its side, and Venus rotates retrograde. All orbit the same direction.

That's the basics, as I understand them. It's been a while since I calculated this stuff. So I welcome corrections.