SOLAR SYSTEM

Detailed explanation-1: -As the nebula collapses further, instabilities in the collapsing, rotating cloud cause local regions to begin to contract gravitationally. These local regions of condensation will become the Sun and the planets, as well as their moons and other debris in the Solar System.

Detailed explanation-2: -Angular Momentum All clouds rotate, at least a little, due to gravitational shearing in the galaxy’s disk. And if a cloud rotates, it has angular momentum: L   mrv. And remember that angular momentum is conserved. So if a rotating cloud collapses (r gets smaller) than it must spin faster (v gets bigger).

Detailed explanation-3: -The primary source of spin in nebulae (also for galaxies), is torque from the local environment. Nearby nebulae, clouds, stars, etc can exert a net torque on the nebula (or galaxy) giving it angular momentum. This is the primary source of spin for nebulae.