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Why Use an Infrared Telescope?

by Alan Tokunaga

Infrared radiation is heat. It is electromagnetic radiation that is at longer wavelengths than the optical radiation we see with our eyes. Although we cannot see infrared radiation, we can feel it. The heat from the stove in a kitchen is infrared radiation that we feel with our skin.

Infrared astronomy gives scientists the ability to measure the temperatures of planetary bodies, stars, and the dust in interplanetary space. There are also many molecules that absorb infrared radiation strongly. Thus the study of the composition of astrophysical bodies is often best done with infrared telescopes.

Optical and infrared telescopes are very similar in construction, but infrared telescopes like the IRTF are designed to minimize the amount of heat that is emitted by the telescope itself. All new telescopes are built to operate at both optical and infrared wavelengths.