As part of the global fight against Light Pollution, Globe At Night recruit ordinary citizens twice a year to measure the light pollution in their neighbourhood. All you have to do is print out their maps, and compare them to a certain area of the sky (This time around, it’s the constellation of Orion). Different levels of light pollution drown out different numbers of stars, so well-known constellations take on different appearances depending on how bright the sky is in your area. Simply match one of the reference diagrams to what you actually see, then go online to submit your results. They will also ask you for your exact location (in Latitude and Longitude – easily read off any GPS device, or google maps, or an atlas) and once the sampling period ends, they generate a map displaying the severity of the problem worldwide. It takes five minutes, it’s fun, and it contributes to real scientific research. So click here, and do your part to preserve our dark skies!