Spitzer Space Telescope (SST)

Artist's impression of Spitzer
Credit: NASA/JPL-Caltech

The Spitzer Space Telescope (SST) is an infra-red telescope, launched by NASA in 2003. Spitzer orbits the Sun once every 373 days, trailing behind Earth's orbit, which takes 365 days (one year). Since most infra-red light is absorbed by water molecules in the Earth's atmosphere, infra-red telescopes operate at very high altitudes - or, like Spitzer, in space.

Some facts about the telescope:

  • Observatory location: In orbit around the Sun
  • Mass: 950 kg
  • Mirror diameter: 0.85 metres
  • Launch date: 25th August 2003
Infra-red image of the helix nebula taken by Spitzer
Infra-red image of the Helix Nebula
Credit: NASA/JPL-Caltech

The mission was planned to operate for 5 years, however Spitzer is still in use today. The telescope uses liquid helium to cool its instruments, and Spitzer was launched with enough liquid helium to last 5 years. Without this cooling mechanism, most of the telescope's instruments are no longer usable. However, two of the short-wavelength instruments are still in operation. This phase is called the Spitzer Warm Mission.

Spitzer's infra-red cameras were used to photograph star formation, planet formation, galaxies, and distant objects such as quasars. In 2005, Spitzer became the first telescope to ever capture light from an exoplanet. It could not form the light into an image of the planet, but this was the first time an exoplanet had ever been directly seen.