“Vision is the art of seeing what is invisible to others.” -Jonathan Swift
If you want to look out into the Universe, all you need to do is gather the light it gives off. Unless, of course, there’s something in the way. For about 20% of the sky, that’s exactly the story for our own Milky Way galaxy, where the neutral gas and dust block most of the visible light everywhere we look, preventing us from observing the Universe beyond.
However, this doesn’t mean we have no options: the gas and dust might block visible light, but longer wavelengths like radio and infrared can pass right through. Recently NASA’s Wide-field Infrared Survey Explorer (WISE) mission mapped the entire sky in the infrared, including the entire galactic plane. It not only found many background galaxies, but it gave us a new window into what’s possible. Perhaps, with future missions, we’ll discover the cause of the “great attractor” phenomenon after all.