Infrared waves are light waves that are not visible to the human eye. Infrared was discovered in 1800 by William Herschell during his experiment on colored light temperature. There are numerous objects in space that can only be seen using special infrared viewing instruments.
Infrared waves are not part of the visual spectrum due to their longer wavelengths and warmer temperatures. Herschell discovered this by measuring the heat of colored thermometers and noticing that thermometers warmer than red were emitting light that was not visible.
Infrared objects in outer space can be viewed using the James Webb Space Telescope. In the Orion nebula, 2,300 planet-forming disks were discovered by spotting the warm, infrared light of their dust. New stars have also been spotted using the infrared telescope.