Got a few minutes to spare? You've got enough time on your hands to help a group of researchers tackle a massive problem. Cities at Night is a project aiming to recruit help from ordinary citizens in classifying images of Earth at night taken by astronauts aboard the International Space Station. An effort of Universidad Complutense de Madrid staff and students, their main goal is to better understand and reduce light pollution.

There are several ways you can help out. By using a few different web applications, users can aid in identifying points of light as cities, stars or aurora - something that algorithms can't do reliably. Help is also needed in geo-referencing night photos of Earth by matching up features in images with corresponding map locations.

Identifying these images will help researchers measure light pollution, with the hopes that they can use this information to help make cities more efficient with lighting. It's not a bad way to spend a ten minute break either.