A telescope designed to observe in the infrared section of the electromagnetic spectrum. Infrared telescopes look like optical reflecting telescopes and operate in a similar way. The infrared radiation is collected and focused by mirrors onto detectors sensitive to infrared. One problem with infrared telescopes is that the telescope itself is a source of unwanted infrared radiation, but this is minimised by cooling the components of the telescope with liquid nitrogen for near infrared observations and with liquid helium for the far infrared.
Telescope designed to detect infrared radiation. Many such telescopes are designed to be lightweight so that they can be carried above most of Earth's atmosphere by balloons, airplanes, or satellites.
Telescopes designed to detect infrared radiation.