For city dwellers, our connection to what’s above—to the stars, the planets, and the rest of our galaxy—can be fraught. We live in a cloud of artificial light that obscures our vision. Stargazers, both professional and amateur, have formed organizations to fight the spread of this pollution, mapping out its extent and studying its ill effects; our use of electricity has immensely changed the natural patterns of life on Earth. Today, nearly the entire populations of the United States and Europe live beneath light-polluted skies. Across the world, almost a third of humanity can no longer see the Milky Way at night.
Nevertheless, astronomers populate the globe, looking up and encouraging others to do so, too. The Amateur Astronomers Association of New York, for example, established in 1927, includes seven hundred members. Some bring their telescopes to public spaces throughout the city on warm summer nights. Others gather in clusters, cramming into cars and driving away from the city, searching for darker skies. Our world is getting lighter, but the inky universe above is still there, waiting for us to turn off our lights and lift our eyes.