How does the Spitzer Telescope work?
"Basic" Introduction to Spitzer Space Telescope10 − 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. (Can you name other wavelengths longer than IR? Really long wavelengths include radio waves and microwaves. And, in case you were wondering, shorter wavelengths include UV, x-rays, and gamma rays.)
Unfortunately for earthbound IR astronomers, most of this IR radiation is absorbed by the Earth's atmosphere. Thus IR radiation cannot be observed from the ground, so the solution decided on was to launch a satellite into space. Spitzer was the last of the Great Observatories to be launched. On August 25th, 2003, it was launched into space by a Delta II rocket from Cape Canaveral, Florida.Movie about the Earth-trailing orbit.) This was done because the instrument must be kept very cold, so it was best to keep it further away from Earth. If you are wondering why 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 IR signals from space (this is sometimes called heat interference or noise...it would be sort of like trying to observe in visible wavelengths with a telescope made out of fluorescent light tubes.) 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.
With all of these specialized instruments on board, the Spitzer telescope gives us a unique picture that our eyes cannot see. For example, it can detect IR light through vast, dense clouds of gas and dust which block visual light. Inside of these dense clouds of gas there can be new stars forming or newly forming planetary systems. Spitzer can look at really dim, smaller stars or at giant molecular clouds. It can help scientists identify which molecules are present in the clouds because certain molecules have unique signatures in the infrared. One of the important molecules that Spitzer can identify is called a PAH (polycyclic aromatic hydrocarbon). PAHs are one of the important molecules found in the interstellar medium (ISM). For more information, check out Studying Polycyclic Aromatic Hydrocarbons.
Brief chronology of Spitzer
- Spitzer mission studies began in the late 1970s.
- The success of the IRAS all-sky survey (1983) needed follow-up with a pointed observatory such as Spitzer.
- Three Spitzer instruments were selected in 1984.
- The project wasnearly cancelled several times; it survived a major descope in early 1990s.
- Spitzer had a successful launch on August 25, 2003.
- Nominal Operations began December 1, 2003.
- Got a new name (SIRTF became Spitzer) on December 18, 2003.
- We expect a 5.5 year cryogenic mission. (Observing at our longest wavelengths depends on the liquid helium we carry on board to cool down the telescope. When the He is gone, then only the first two bands of IRAC (3.6 and 4.5 microns) will still function. We will continue to operate at these bands until NASA cuts off our funding, or until we can no longer communicate with the spacecraft.
- Spitzer website
- Spitzer history
- Spitzer newsroom - current and past press releases
- Spitzer podcasts - also available in iTunes
- Cool Cosmos IPAC missions gallery
- What is Spitzer observing right now??
- Build your own model of Spitzer!
- Spitzer Launch Simulation Video (when this video was made, Spitzer was still called SIRTF)
- The real Spitzer launch, seen in infrared. This clip shows the launch of Spitzer, including the cooling of the plume after the rocket flies out of frame. The reason it looks like the clouds light up and come down to meet the rocket is because the clouds are reflecting (scattering) the bright infrared light of the hot rocket engines below.
- Movie on the Earth-trailing orbit
- Data collection and retrieval from Spitzer video