The primary goal of the European Space Agency’s Planck satellite is to provide a map of the cosmic microwave background with unprecedented precision. But along the way, you have to take into account that there is stuff in between us and the farthest edges of the universe — in particular, there’s all sorts of dust here in our home galaxy. You can even become famous just studying dust; one of the most highly cited papers in all of astrophysics is a 1997 map of galactic dust.
Dust isn’t only an annoyance — it’s also pretty. Planck hasn’t released any data about the CMB yet, but they just released a map of the cold dust in our local vicinity, looking for all the world like an abstract expressionist painting. (I want to suggest a particular artist, but my mind is blanking.) Click to embiggen.
It’s a false-color image, of course; the dust is very cold (tens of degrees above absolute zero), and the image is constructed from microwaves, not from visible light. You can see the plane of the galaxy, and the filamentary structures arising from all the churning of the interstellar medium from supernovae, star formation, magnetic fields, and so on.
Okay, pretty time is over. Let’s see the CMB.