Ray Vingnutte wrote:
http://www.spaceref.com/news/viewpr.html?pid=17432


Perhaps these disks need "seed crystals" as it were to start the
planetary formation process. That is, maybe asteroids or comets need
to drift in from interstellar space to start attracting the dust and
gas and become the cores of future planets. This would be a probable,
but nonetheless chance process.

Double-A