Spitzer Space Telescope

General Background

The Spitzer Space Telescope was the last of NASA's Great Observatories to be launched in August, 2003. It is a thermal infrared telescope that can view into regions of the Universe that are obstructed by dust and clouds of gas (like the centers of galaxies, stars, and planet formations). It can also detect cooler objects such as small stars and extrasolar planets. Spitzer has a heliocentric orbit, meaning that it trails and drifts away from Earth's orbit.

Spitzer is a specialized Cassegrain reflector telescope, where both the primary and the secondary mirrors are hyperbolic, which is used to eliminate optical errors. Spitzer was the first telescope to detect water on a planet orbiting a star outside of our Solar System.

Spitzer's Three Instruments (click instruments below to expand)

       1. —IRAC (Infrared Array Camera)

IRAC is a near- and mid- infrared camera. It has four detectors that measure four different light wavelengths (3.6, 4.5, 5.8, and 8 micrometers) and therefore can take four simultaneous images.

The image below was taken by IRAC of the Black Widow Nebula.


       2. —IRS (InfraRed Spectrograph)

IRS is a spectrograph that provides high and low resolution spectroscopy at mid-infrared wavelengths. It is used to detect what which or molecules are present in objects that are emitting infrared light.

      3. MIPS (Multiband Imaging Photometer)

MIPS is a far-infrared camera also capable of basic spectroscopy (much like IRS).

Spitzer's Exoplanet Explorations

Spitzer detects exoplanets by first collecting the infrared light emitted by the star and planet combined and then capturing the light when the planet passes behind the star, as part of its orbit. The planet's light emission can then be measured and used to determine the planet's spectrum. Spitzer can also be used to determine temperature, atmospheric turbulance (wind), and atmospheric composition of exoplanets.