IRAS was able to discover in excess of 500,000 infrared sources, including many galaxies, and has discovered shells of debris surrounding stars that show the early stages of planetary formation, with debris similar to that later found as the Kuiper belt that encircles our Solar System beyond the orbit of Neptune. Based on these findings, researchers have concluded that the majority of galactic radiation is emitted in the form of infrared radiation that is generated when light from young stars is absorbed by interstellar dust and then radiated from the dust in the form of heat.
IRAS was able to identify in excess of 500,000 infrared sources, including numerous galaxies, and has discovered shells of debris surrounding stars that show the early stages of planetary formation, with debris similar to that later found as the Kuiper belt that encircles our Solar System beyond the orbit of Neptune. Based on these findings, researchers have concluded that the majority of galactic radiation is emitted in the form of infrared radiation that is generated when light from young stars is absorbed by interstellar dust and then radiated from the dust in the form of heat.