 In 1993 , the Hubble Space Telescope first observed the Orion Nebula . Since then , the nebula has been a frequent target for HST studies . The images have been used to build a detailed model of the nebula in three dimensions . Protoplanetary disks have been observed around most of the newly formed stars in the nebula , and the destructive effects of high levels of ultraviolet energy from the most massive stars have been studied . 
