Planets and other small rocky structures in our solar system are believed to form from clouds that shrink into pancake-like disks. Although this is the general theory, some details of about the process of forming planets are not clear. This article summarizes a new and improved model that describes how these disks of matter coalesce to form small rocky bodies. These small bodies later develop into larger structures like planets and asteroids.

http://www.raa-journal.org/raa/index.php/raa/article/view/469