COSMIC INFRARED BACKGROUND DISCOVERED. The Cosmic Microwave Background Explorer (COBE) collaboration, which six years ago reported the first evidence for structure in the microwave background (Update 77), has now finished a mapping of the whole sky at ten different infrared wavelengths, from 1 to 240 microns. After carefully subtracting the expected contributions from our own solar system and the Milky Way galaxy (understanding the foreground sources of infrared was itself a process that took years) what is left over is the cosmic infrared background, the cumulative IR radiation (amounting to one-half to two-thirds of the total light) coming from all the stars that have ever existed. Much of the light that reaches the detector has been scattered in transit by dust. The cosmic IR background appears uniform (no structure is apparent) and bears no information about when during the history of the cosmos the radiation was emitted. Nevertheless, the observations have helped to provide rough limits on the amount of star formation in the universe and confirms the suspicion that a lot of star birth has been obscured by dust. Michael Hauser, now at the Space Telescope Science Institute, delivered the main COBE report at last week's meeting of the American Astronomical Society (AAS) in Washington, DC.(Image at Physics News Graphics website.)