Figure 3-36 Spitzer Space Telescope (a) The mirror assembly for the Spitzer Space Telescope showing the 85-cm objective mirror. (b) Launched in 2003, this Great Observatory is taking images and spectra of planets, comets, gas, and dust around other stars and in interstellar space, galaxies, and the large-scale distribution of matter in the universe. Inset: An infrared image of a region of star formation invisible to optical telescopes.