A composite image of the Orion Nebula using insets to show protoplanetary disks (proplyds) around forming stars. Images such as this indicate that about half of all forming stars have rotating disks similar to the Solar Nebula out of which our planetary system is thought to have formed. (NASA, ESA, M. Robberto (STScI/ESA), the HST Orion Treasury Project Team, & L. Ricci (ESO))