Autumn is the ideal time to get a sense of humanity’s place in the universe.
All it takes is a late afternoon drive to the dark skies of rural Ohio to watch the sunset until the cosmos appears in all its glory. A set of binoculars provides an even better view.
As darkness falls, look up with just your own two eyes. The western sky glows with a strange, convoluted band of silvery light. The summer Milky Way lingers in the west.
You are looking at the distant stars of your own galaxy, your cosmic locality. Your home star, the sun, is but one of the Milky Way’s 300 billion stars. You need only your binoculars to cause that band to explode into countless stars.
The Milky Way is shaped a bit like an Olympic discus, wider at the center and tapered at its edges. Our galaxy measures 100,000 light years from side to side. (One light year equals about 5.9 trillion miles.) Turn on a flashlight on one side, and the light takes 100,000 years to reach the other side.
Now, aim your flashlight at the moon. Its light takes a tad more than a second to travel from here to there. Compare that second to 1,000 centuries, and you’ll begin to understand the enormous size of your galactic neighborhood.
We live near the edge of the Milky Way. As we stare into it, the Milky Way’s stars, dust, and gas obscure our vision of the rest of the universe. To understand the universe’s structure and texture, we must look away from the densest part of the Milky Way.
Therefore, just after dark, look east to find the constellation Andromeda. Only a thin veil of the Milky Way’s dust and gas obscures the view. Far beyond the constellation’s stars, you’ll see a cigar-shaped light patch called the Andromeda Galaxy.
You are seeing the farthest thing a human eye can see.
Granted, the galaxy doesn’t look like much to the unaided eye, but it will fill the field of most binoculars. Andromeda is tilted partly on its side from our Milky Way vantage, accounting for its oval shape.
At perhaps 200,000 light-years wide, the galaxy is twice the diameter of our Milky Way. Astronomers put Andromeda at about 2.5 million years away. Fifteen Andromeda Galaxies or 30 Milky Ways could be placed end-to-end into the enormous gulf between the two.
After a lifetime of stargazing, one simple fact leaves my mind gasping for air.
The universe is littered with trillions of galaxies like the Milky Way and Andromeda. If you spent your entire life, a hundred lives, looking at every galaxy you could see in a telescope, you would see only a tiny fraction of the galaxies in the universe.
All those galaxies would be more distant than that faint smear of light in the constellation Andromeda.
Look upward at the nighttime sky just once in your life. Stare long enough, and perhaps you will get a hint of humanity’s place in the universe.
You are a tiny, fragile creation compared to the most inconsequential star. Your physical body is mortal and weak, but your mind can instantly measure out the universe.
You were given a mind capable of comprehending and sharing in the universe’s vastness.
People are concerned with the details of their daily lives, as well they should be. They are also concerned in a larger sense with where our nation and our world are headed.
I worry about those things myself. How can I protect my family, the environment in which we all must live, and our nation’s economy?
However, a lifetime of looking at the sky has led me to believe with firm conviction this inescapable conclusion:
Once people experience our extraordinary place in the universe, the strength and fragility of the miracle we call life, the immense beauty and cold efficiency of the cosmos, the minuteness of our planet and our tenuous presence on it, and the power and powerlessness we have over the only planet we have ever called home, I know deep in my heart of hearts, where it counts the most, that we will somehow find the courage to do what is best for ourselves, our families, our nation, and our fragile species.
Staring upward at the cosmos is an excellent place to start that journey.
Tom Burns is the former director of the Perkins Observatory in Delaware.
