An infrared telescope is a type of telescope that is designed to detect and observe infrared radiation, which is a form of light that has longer wavelengths than visible light. Infrared radiation is typically associated with heat—objects that are not hot enough to emit visible light (like warm dust clouds, cool stars, and planets) can still emit strongly in the infrared.
What Infrared Telescopes Observe:
- Cool celestial objects: These include brown dwarfs (failed stars), planets, and comets that don’t emit much visible light but shine brightly in the infrared.
- Star-forming regions: Infrared telescopes can peer through thick clouds of gas and dust that often obscure young stars in visible light.
- Distant galaxies: Some galaxies are so far away that their light is redshifted into the infrared spectrum, and infrared telescopes are key to detecting them.
- Dusty regions of space: Infrared is excellent for observing regions with lots of interstellar dust, like the centers of galaxies, which are often hidden in optical wavelengths.
- The early universe: Because of the redshift effect, light from the early universe stretches into the infrared as it travels across space and time.
Why Use Infrared Telescopes in Space?
Earth’s atmosphere absorbs much of the infrared radiation from space, so many infrared telescopes—like NASA’s Spitzer Space Telescope or the James Webb Space Telescope (JWST)—are placed in space to get a clearer, uninterrupted view.