I posted a lot of infrared images taken by WISE, the Wide-field Infrared Survey Explorer, on Prime Focus during its run. The orbiting space telescope has since run out of the coolant required for its infrared detectors and has since been put into its hibernation mode, but there are still plenty of images being released. Take, for example, the above image of Sharpless 284 (Sh 2-284), a nebula in the constellation Monoceros. This is a false-colour image of infrared light, which is invisible to the naked eye: different colours represent different infrared wavelengths. Red is 22 µm and green is 12 µm; these wavelengths mostly represent emissions from dust. Cyan is 4.6 µm and blue is 3.4 µm; these wavelengths mostly represent starlight. Image credit: NASA/JPL-Caltech/UCLA.