Imagine your shop is in a remote spot in the depth of winter location, say New Hampshire, and you worked too late again. You turn out the lights, go out and shut the door behind you.  You stop, shake your head and look up, waiting for your eyes to adjust to the dark and your mind to calm down.  The cold air rustles your mind awake, and your hearing becomes acute.

Gradually the sky starts to fill with points of light. You see the brightest stars right away. Successively dimmer stars appear first in your peripheral vision, so when you try to look at them directly they disappear until you look away again and there they are, teasing. Your peripheral vision is much more light-sensitive than your central vision.

Surprisingly, with the naked eye it is possible to see only about five thousand stars in the sky. So if you start feeling cosmic about what you see looking up, just keep in mind that our galaxy has about a half trillion stars, so you are missing 99.999999% of the real show, and that is just our own galaxy.

Just how big is a billion? Or a trillion for that matter? It is hard at first to think about numbers like these, but there are mental pictures that help. It turns out a cubic foot of typical beach sand has about a billion grains. That is seven and a half gallons. Multiply that by one thousand to get a trillion, and you have about a small backyard swimming pool’s worth of sand.

Here is another picture of a billion I like from biology - The DNA in each and every cell in your body stretches out to a length of about ten feet, and its diameter is about one-billionth of its length. So if your DNA were scaled up to the diameter of a pencil, it would stretch from New York to San Francisco. But frogs get the last laugh – their DNA is three times as long as ours.

As deep and beautiful as the winter night sky is, our eyes are barely catching a hint of it. The Andromeda galaxy is our nearest neighbor and is twice as large as ours with about a trillion stars. Yet, to our unaided eye, those trillion stars appear as a mere smudge along the edge of the Milky Way. The image above shows a better view of Andromeda through a big telescope. The dust particles you see all over this picture of Andromeda are actually individual stars in our own galaxy. That “mist” you see surrounding Andromeda is actually made up of individual stars – there are just so many of them that they look like smoke. The mind boggles, but this is just the beginning.

This image is known as the Hubble Ultra-Deep Field, and shows what is in that one little blue square by the moon.

Other than a couple of bright nearby stars from our own galaxy, every object in this image, ranging from small discs down to dust motes, is a complete galaxy.