 Every night you look in the southwest, they're getting slowly closer and closer together. And on the 21st of December, they'll be, get a load of this, a tenth of a degree apart. What does that mean in Earth terms? It means about a fifth the diameter of a full moon. It won't happen again until the year 2080, and it hasn't happened since the year 1623. But, George, we begin with space. How dark is space? You probably would say that space is very dark, right? Well, recent observations made with the Pluto-passing New Horizons spacecraft