Say goodnight, Spitzer. Farewell to a groundbreaking space telescope.

The mission was only supposed to last for 2 1/2 years. But, more than 16 years later, NASA’s Spitzer Space Telescope has far exceeded expectations. 

Since launching in August 2003, Spitzer has facilitated discoveries that its designers never imagined. Peering at the universe in the infrared, the space telescope has unveiled stellar nurseries, spotted the most distant galaxies, and revealed the contents of exoplanet atmospheres. But on Thursday, Jan. 30, engineers are signaling to Spitzer to power down, as NASA shifts resources toward the impending launch of its successor, the James Webb Space Telescope.

With wavelengths longer