The Spitzer SpaceTelescope
The Spitzer Telescope
The Spitzer telescope was launched in August 2003. It consists of an 0.85-meter scope that is cryogenically cooled because it uses infrared technology, meaning that it picks up infrared rays, a form of heat radiation. It is cooled to near absolute zero (-459 degrees Fahenheit) so that heat from the scope, the earth or the sun does not affect the scope's infrared ray reception.
Spitzer Space Telescope
The vast majority of information in the Universe is in the form of electromagnetic radiation (light). And much is in the infrared spectrum, which cannot be seen with the naked eye or even with visible light telescopes. The amazing part is that while only a small amount of the infrared information reaches the Earth's surface, astronomers, by studying this small range of infrared wavelengths, have unearthed a plethora of new information.
Infrared radiation, having wavelengths which are much longer than visible light, can pass through dusty regions of space without being scattered. Many objects in the universe, which are much too cool and faint to be detected in visible light, can be detected in the infrared. These include cool stars, infrared galaxies, clouds of particles around stars, nebulae, interstellar molecules, brown dwarfs and planets.
The Astronomy of Infrared Observation
The highly sensitive instruments provide a unique view of the Universe and allow astronomers to peer into regions of space which are hidden from optical telescopes. The issues is that many areas of space contain large vast, dense clouds of gas and dust which can block the optical view. Infrared light, however, can penetrate these clouds, and this allows instruments to peer into regions of star formation, the centers of galaxies, and into newly forming planetary systems that are otherwise hidden.
It also brings information about smaller stars which are too dim to be detected by their visible light, or exo-planets, and giant molecular clouds; normally these are cooler space objects, so their infrared signature will be different. And note, many molecules in space, such as organic molecules, have their own unique infrared signatures.
The Cygnus Red Region
Why InfraRed Astronomy?
Because of the expansion of the Universe, cosmic red shift energy has shifted to longer wavelengths. Consequently, most of the optical and ultraviolet radiation emitted from stars, galaxies, and quasars since the beginning of time now lies in the infrared. And because of the finite speed of light, objects at high red shifts look as they appeared when the Universe and the objects were much younger. As a result of the expansion of the Universe, most of the optical and ultraviolet radiation emitted from stars, galaxies, and quasars since the beginning of time now lies in the infrared.
Infrared astronomy adds a great deal of knowledge about distant objects because it picks up details that optical telescopy does not. But Spitzer is one of four observatories in the NASA Observatories Program. The program has four orbiting observatories, each one designed to look at the Universe by focusing on a different kind of light: visible, gamma rays, X-rays, and infrared.