Caption Red, green and blue correspond to the 160-micron, 100-micron and 70-micron wavelength bands of the Herschel’s Photoconductor Array Camera and Spectrometer, PACS. Glowing light from ...

Thermal imagers rely on the emission of thermal or infrared energy by all objects above 0 Kelvin. They detect energy emissions (heat) in the infrared wavelength spectrum of 1 micron to 100 microns.