NASA's new 'Black Marble' images of the nighttime Earth aren't so black. They reveal that our globe is heavily littered with excessive and wasteful lighting that produces light pollution – a bright glow over our cities that not only masks the stars but wastes vast amounts of energy. Fixing the problem would cut greenhouse gas emissions, save money, lessen our impact on the natural world, and improve visibility on the ground.
Revealed in the images, collected by the Suomi National Polar-orbiting Partnership satellite, is the upward-directed light emitted from our cities, highways, natural gas burn offs and more. The images show cities that are brighter than they need to be because much of our light is poorly aimed. In the United States alone, billions of dollars are wasted annually illuminating the night sky instead of sidewalks and roadways on the ground.
"The new 'Black Marble' images of our Earth show that there is still much work that needs to be done in tackling the problems of light pollution," says Bob Parks the Executive Director of the International Dark-Sky Association (IDA). "The impact of our lighting at night extends well beyond astronomy," he continued.
Excessive and poorly directed lights can create deep shadows that are unsafe for pedestrians, cause hatchling sea turtles to lose sight of the ocean, and confuse migrating birds causing them to fly into buildings. Light pollution has other far-reaching effects unknown to many who continue to use ineffective lighting and inadvertently add to light pollution in their communities. Although the problem is serious, the solution for many is as simple as changing bulb wattage, using motion sensors, or installing hoods over bare bulbs.
IDA recommends that all outdoor lighting be directed downward. It should only be used when it is actually needed and in the amount that is necessary. With proper lighting we can dim the 'Black Marble' and return the stars to the skies overhead.
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