Many of you have probably already seen this image which is actually a composite of hundreds of satellite images from NASA. When I look at this image, I immediately think, “look at all of that wasted electricity!”
The International Dark-Sky Association estimates that approximately 22,000 gigawatt-hours of electricity is consumed by wasted outdoor lighting annually, costing an estimated 2.2 billion dollars! Showing this image to your students is a great way to introduce the topic of light pollution, which will be one topic featured here later this month. For now, maybe you can prompt your students to think about the potential consequences of light pollution.