ocr: INFRARED RADIAIION Electromagnetic radiation whose wavelength is longer than that of visible light, but shorter than radio waves, from 0.7 micrometres to one millimetre. Infrared radiation cannot be seen, but it is felt as heat. Most intrared radiation is absorbed by the atmosphere, especially by water which is in the form of steam. That is why telescopes studying infrared radiation must be placed atop high mountains or in satellites. Infrared wavelengths enable US fo take pic- tures of objects that are out of reach of visible light, such as the centre of the Milky Way. In- frared radiation is ...
