For centuries, people gazing at the sky after sunset could see thousands of vibrant, sparkling stars. But ＿＿（41）＿＿ , you'll be lucky if you can view the Big Dipper. The culprit: electric beams pouring from homes and street lamps, whose brightness ＿＿（42）＿＿ the night sky. In the U.S., the so-called light pollution has gotten so bad that, by one estimate, 8 out of 10 children born today will never ＿＿（43）＿＿ a sky dark enough for them to see the Milky Way. There is hope, however, in the form of astrotourism, a small but growing industry centered on ＿＿（44）＿＿ in the world's darkest places. These remote sites, many of them in national parks, offer stunning views for little more than the cost of a campsite. And the people who run them often work to reduce light pollution in surrounding communities—asking towns to ＿＿（45）＿＿ their street lamp, for example, or urging residents to draw their blinds.