Over the last decades, light pollution, the pollution of naturally dark skies by artificial light, has intensified, without regard to its potential impacts on humans and the environment. While some scientific investigation of light pollution and its effects has taken place, it has been narrowly focused within astronomy or the effects on single organisms.

Germany’s Cosalux GmbH developed the Loss of the Night project and app to help scientists measure and understand the effects of light pollution. Citizen scientists can identify visible stars in the sky and contribute to a worldwide citizen science project to create a database for research on health, environment and society.

Loss of the Night allows users to measure light pollution in three steps. The first is an arrow that guides users to a star, similar to a compass. The app then asks users to select visible stars in various constellations and submit their data once observations have been completed. With assistance from stargazers, researchers hope to learn how lamp design contributes to light pollution. Measurements from the app are sent anonymously to the Globe at Night database, a citizen science project that launched in 2006.