Portal:Space exploration/Picture/Week 7 2007

Credit: NASA

The Infrared Astronomical Satellite (IRAS) was a space-based observatory that performed a survey of the entire sky at infrared wavelengths. IRAS mapped 96% of the sky four times, at 12, 25, 60 and 100 micrometre wavelengths, with resolutions ranging from 0.5' at 12 micrometers to 2' at 100 micrometers. It discovered about 500,000 sources, many of which are still awaiting identification.