This infrared image from NASA's Spitzer Space Telescope shows a cloud of gas and dust full of bubbles. (NASA / JPL-Caltech)

Next week, the last of four NASA space-based observatories will retire. The Spitzer Space Telescope brought the universe into a new light (literally), revealing images of planets, solar systems, stars and more in infrared renderings that human eyes aren't able to see otherwise.

"Infrared light provides unique perspectives on the universe," said Michael Warner, a project scientist for Spitzer at the Jet Propulsion Laboratory in Pasadena. "In the infrared, we have some unique things we can do to augment our understanding."

To that end, Spitzer - which launched in 2003 - allowed scientists to see stars in distant galaxies, planets that might be too cool to produce much light, and parts of the universe that are otherwise blocked by small particles.

"We call these the old, the cold, and the dirty," said Warner.

The other space observatories in Spitzer's class include the Hubble Space Telescope, Compton Gamma-Ray Observatory and the Chandra X-Ray Observatory. In 2016, NASA announced that Spitzer and Hubble had identified GN-z11, the most distant galaxy scientists had observed to date.

Spitzer will retire on Jan. 30. Here are some of the images it has taken over the years. Live long and prosper, old friend.

Read more:

NASA's Spitzer Telescope Revealed Colors Unseeable By The Human Eye. It Retires Next Week - LAist