Sputnik, 1957. How shocking the Russians first in space! As a young amateur astronomer I had quite another impression. I was overwhelmed by the realization that in my generation the night sky was changed forever, irrevocably blemished, and would never again be “natural,” the pristine inheritance people had taken for granted over millennia. Now, of course, there are many hundreds of satellites and thousands of bits of “space junk” cluttering the sky. But the space program did not destroy astronomy; on the contrary, the Hubble telescope and its successors have greatly advanced it. And there is something proud and thrilling about watching the International Space Station transit the sky. Satellites and space debris may be a nuisance to professional and amateur astronomers attempting to photograph deep space. But photography has greatly advanced as well. New digital cameras are many times more sensitive than film; multiple time exposures can also now be integrated and “stacked” by computer. Contemporary backyard astronomers can produce images that rival those of professional observatories.

Yet, there is another menace to earthbound astronomy, which comes not from the sky but from the spread of electric illumination over the planet: so-called “light pollution.” Pictures of earth taken from orbit show a planet so lit up at night that few sizable dark areas remain. It is worst, of course, in large cities, where many people spend their whole lives never seeing the Milky Way. Education facilities in big cities, even with superb telescopes, are severely limited by ambient urban light. To see the heavens as they appeared, say, five hundred years ago, you have watch a simulation in a planetarium, ironically sealed from the real sky.

Because the planets are bright, Galileo would have made his discoveries even if handicapped by current light pollution. But our nearest galactic neighbor, the Andromeda Galaxy, is barely discernable to the naked eye; only in the last century did it become evident that this is a separate system, one of countless many outside our own. Only then could the picture emerge of an expanding universe of billions of galaxies beyond our own. Most of these galaxies, and the gaseous nebulae within our own system, are extremely faint. Could such discoveries have been made under current conditions of light pollution? Even the great Palomar telescope, responsible for so many of these discoveries, has been crippled by its location between merging urban conglomerations. Many of the important optical telescopes are now clustered on the high volcanoes of Hawaii, where nearby towns have cooperated with programs to control light pollution through use of shielded yellow-vapor street lights.

We are blessed to have no public street lights in our rural community. We are fortunate to be able to go out on a clear moonless night and still see a glorious starry sky—part of the precious experience of nature that attracts us to this place. I encourage everyone to help keep our night skies dark. If you have an outdoor light that burns all night, please consider turning it off when you are not actually using it. You’ll save on the electric bill too! With house lights dimmed, bundle up and go outdoors after dark, let your eyes adjust, and see for yourself the splendors of the heavens!