1. Spitzer Space Telescope
The Spitzer Space Telescope is the fourth and final of NASA’s Great Observatories, each observing the universe in a different kind of light.
It measures infrared light from the solar system and distant galaxies.

2. Basic Facts Launched August 25, 2003. Expected Duration: 5+ years.
Orbit: earth-trailing, heliocentric.
Telescope: 85 cm diameter; largest infrared telescope ever launched into space.

3. Innovations
Because infrared is primarily heat radiation, the telescope must be cooled to near absolute zero: protected from the Sun’s heat and infrared radiation from Earth.
It carries a solar shield and orbits in an earth-trailing solar orbit, which allows the telescope to cool rapidly and has reduced the cost of the mission.

4. Infrared Light Our eyes can only see visible light.
Infrared light is not visible to our eyes but can be detected by instruments such as the Spitzer Space Telescope.

5. Infrared Energy
Spitzer will obtain images and spectra by detecting infrared energy or heat radiated by objects in space between wavelengths of 3 and 180 microns. (One micron = meter)
Infrared radiation is blocked by the Earth’s atmosphere and cannot be observed from the ground.

6. Infrared Radiation

7. A Unique View of the Universe
Infrared light can penetrate clouds of gas and dust.
It allows us to view regions of star formation, and centers of galaxies.
Cooler objects are also visualized.

8. Orion as seen by Spitzer

9. Drifting behind the Earth
The Observatory drifts behind the Earth as it circles the Sun.
It drifts away from the Earth at the rate of .1 AU per year.
Ambient temperatures are 30 to 40 K.
It carries less cryogen (coolant) than if in Earth orbit.

10. Spitzer’s view of the sky
Andromeda Galaxy

11. Sombrero Galaxy

12. Cosmic Mountains of Creation

13. Cosmic Classroom

14. Cool Cosmos http://coolcosmos.ipac.caltech.edu/
The Spitzer Space Telescope has an Education and Outreach website that contains background on infrared light and the telescope itself.