Infrared Astronomical Satellite
January 25, 1983


Image of Infrared Astronomical Satellite

Image Credit: National Air and Space Museum,
Smithsonian Institution (SI Neg. No. 98-15675).


In the early 1800s, the British astronomer Sir William Herschel discovered that sunlight consisted not only of visible light that we can see with our eyes, but also infrared energy beyond the visible spectrum. This led to the development in the 1900s of special telescopes to survey the skies at infrared wavelengths.

The Infrared Astronomical Satellite places such a telescope in orbit above the interference of Earth's atmosphere. Operating for 10 months, two its most significant findings are the discoveries of solid material around the stars Vega and Fomalhaut, located some 26 and 22 light-years from Earth, respectively. This strongly suggests the existence of planetary systems around other stars (later confirmed by future telescope observations).