You can't see them with the naked eye, but teeny-tiny particles exist between stars. This interstellar dust is a particular nuisance to astrophysicists, whose observations and measurements can be distorted by these "cosmic grains." An American University professor is one of 200 people in the world studying the topic; Rebecca Sheir visits U.J. Sofia to learn why, though the particles are small, the issue is pretty darn big.
[Music: "Sky Diver" by Owl City from Maybe I'm Dreaming]