Spitzer Space Telescope


The Spitzer Space Telescope is a space-based infrared telescope studying objects ranging from our Solar System to the distant ends of the Universe. Spitzer is one of four very important telescopes designed to study the universe from space. These are called NASA’s Great Observatories. Perhaps the most famous of these is the Hubble Space Telescope. The other telescopes in the Great Observatories Program are the Compton Gamma Ray Observatory (CGRO) and the Chandra X-Ray Observatory (CXO). Each telescope observes different wavelengths: Hubble observes visible radiation, Chandra observes x-ray radiation and Compton observes gamma ray radiation. Spitzer is designed to observe IR radiation (sometimes called IR energy or simply, heat). It was launched by a Delta rocket from Cape Canaveral, Florida on 25 August 2003 and is still currently in operation (1).


Lyman Spitzer

Lyman Spitzer (June 26, 1914 – March 31, 1997) was an American Astronomer and Physicist, who is most notably known for being the first person, in 1946, to conceive the idea of putting telescopes and have them operate in outer space. Even ten years before the first satellite was launched into space, it was Lyman Spitzer who proposed putting telescopes into an orbit in space. The large space based observatory that he had proposed would soon be the Hubble Telescope. While the majority of his work involved developing and designing the Hubble Space Telescope, his original idea led to the launch of the infrared reading telescope in space now known, in his name, as the Spitzer space telescope.

Make-up of the Spitzer

Spitzer is a relatively small telescope (its diameter is only 0.85 meters) but it is specially designed to detect heat radiation. First, it has three science instruments that are cooled with liquid helium (this is called cryogenically cooled). Second, it can take heat radiated images with a CCD camera or take spectra with a spectroscope. Lastly, it is not in orbit around Earth- it actually follows Earth’s orbit around the Sun, and does not orbit Earth, unique to itself compared to all other satellites and telescopes in orbit.
This was done because the instrument must be kept very cold, so it was best to keep it further away from Earth. The telescope must be kept so cold it is because the telescope is trying to observe heat. If the telescope was warmer, the extra heat would overwhelm the faint radiation signals from space The telescope must also be protected from the heat of the Sun, so it carries a special solar shield and always points away from the Sun.

Moments before Launch of the Spitzer

What the Sptitzer Detects
Because the human eye can only see visible light and wavelengths, between 400-700 nanometers, we must use telescopes that can detect other spectra.
Spitzer is designed to take both images and spectra by detecting infrared wavelengths, this kind of light has longer wavelengths than visible light, beyond 700 nanometers.
Any warm object in space radiates infrared energy. In fact, "warm" really means any object above absolute zero (0 Kelvin or –273C), because any object above absolute zero releases some wavelength of infrared energy. The Spitzer Space Telescope is designed to detect infrared energy between wavelengths of 3 and 180 microns (1 micron (µm) is one-millionth of a meter or 10 − 6 meters. In other words, Spitzer is designed to detect light with really long wavelengths, so long that humans can only detect those wavelengths as heat.
A view of the oldest recorded supernova
A view of Milky Way Galaxy's smaller cousin Messier 83

Why Infrared?

Although telescopes on mountaintops can study certain infrared wavelengths, most infrared radiation is absorbed by the Earth’s atmosphere. Spitzer gets a much clearer view of the wavelengths of infrared light that can be studied from the Earth, and makes it possible to examine the infrared wavelengths that are blocked by the Earth’s atmosphere and invisible to the naked eye. The Spitzer telescope has given us a clearer look at many things in our universe such as star formations, the centers of galaxies, and extra solar planets.

1. http://amazing-space.stsci.edu/resources/explorations/groundup/lesson/scopes/spitzer/
2. http://blogs.smithsonianmag.com/aroundthemall/2009/08/spitzer-telescope-spots-cosmic-destruction/
3. http://www.spacetoday.org/DeepSpace/Telescopes/GreatObservatories/SIRTF/SIRTF.html
4. http://www.scienceclarified.com/
All pictures credited to : http://www.spitzer.caltech.edu/images