The Spitzer Space Telescope lasted over 16 years //

Spitzer is one of four space telescopes operated by NASA known as the Great Observatories. Its fellow “greats” are the Compton Gamma Ray Observatory, the Chandra X-ray Observatory, and the famous Hubble Space Telescope. Combined, the four telescopes were meant to observe the Universe in as many wavelengths of light as possible — ranging from the visible light that we can see, to the kinds of light our eyes cannot register. Spitzer’s charge has been to observe infrared light, a type of light that humans can’t see but can sense as heat. Objects that are faint and super cold can still be seen by the infrared light that they produce, so Spitzer can show us things that might otherwise seem invisible. //

This afternoon, NASA scientists will send a command to Spitzer, telling it to stop taking observations and no longer send pings back to Earth. Conceivably, NASA could wake Spitzer back up again someday, but as more time passes, the tougher that will be. Spitzer will no longer be pointing its antenna back at Earth and sending a strong signal that NASA can pick up. So making a link with the spacecraft will become harder and harder.

But even as Spitzer hangs up its hat, there are still other infrared telescopes in the works — notably, NASA’s next great space observatory, the James Webb Space Telescope. Designed to study the Universe in infrared, the James Webb will be the most powerful space telescope ever when it launches, and will be able see back in time to the beginning of the Universe. //