  What you see in the photograph above is a very small portion of the night sky. A few ordinary stars are visible in the foreground, as we look out from within our own Milky Way galaxy. What we see in the distance, in all directions, is more galaxies like our own...billions of them! Every one of these galaxies is a vast collection of billions of stars, held together by gravity, and separated from other nearby galaxies by millions of light-years. As far as we can see, there are galaxies of stars! They all seem to be moving apart from each other...as if, at one time, they might have been much closer together. The furthest galaxies we can see seem to be about 13-15 billion light-years away. This means that the image we are seeing of these particular galaxies (the light) left those galaxies 13-15 billion years ago. We are seeing them the way they looked then. What they look like now is unknown. |