We like to think of Van Gogh's "Starry Night" as just a great piece of art, but actually it is also the first simulation of the far infrared sky! Diffuse clouds of gas and dust lie above the plane of the Milky Way and are heated to glow in the far infrared. When they were first discovered by IRAS, scientists thought they looked like cirrus clouds and named them the "infrared cirrus." We have to select cirrus-free regions of sky whenever we want to probe really deep.