Posted: Wed, Oct 20, 2004, 10:58 PM ET (0258 GMT)
Observations by NASA's Spitzer Space Telescope have shown astronomers that the process by which planets form around stars is relatively messy, with dust clouds created by the collisions of planetesimals. The infrared space telescope detected very large dust clouds around several stars. Astronomers believe those dust clouds were created when planets forming around those stars collided with one another. The observations confirm existing models of planetary formation, where small particles gradually aggregate into larger bodies that collide with one another; the larger collisions create dust cloud flare-ups seen in the Spitzer images. This process can take over 100 million years, far longer than once thought.

Related Links:

•  SPACE.com article
•  AP article
•  New York Times article
•  Scientific American article
•  NASA press release