Why do planets orbit on such a relatively narrow plane?

Question

when there is so much area under the influence of the sun;
http://www.jpl.nasa.gov/news/news.php?release=2013-278
I can see the possibility of collision explaining to some extent but the area is so vast one would think that there should be something orbiting on another of the limitless planes.

Answer 1

The cloud that formed the solar system collapsed into a disc due to conservation of angular momentum.



http://curious.astro.cornell.edu/question.php?number=205

Answer 2

The protoplanetary disk of gas and dust is thin because energy perpendicular to the disk dissipates due to collisions, but the angular momentum of the material is (mostly) conserved.



As you get further out in the solar system the "disk" gets thicker. Out by the comets, it's spherical.

Answer 3

All the planets were once a planetary nebula from which the Sun and the planets formed and just as how pizza dough forms one plane, that's what happened with the planets, it's the collisions that perturbed them from a perfect plane.