The Star-Spotting Experiment (Stjärnförsöket)

Created March 25, 2020, 10:06 a.m.
Updated Dec. 7, 2021, 2:10 p.m.

Our use of artificial light has dramatically changed the environment in large parts of the world. Scientific studies have shown unexpected and worrying effects on the biology of many organisms as well as on whole ecosystems, but also on human health. The problems of artificial light are commonly referred to as light pollution. In the Star-Spotting Experiment, thousands of pupils, members of outdoor associations, other clubs and members of the public in Sweden, UK, Ireland and Spain contributed to scientific research about light pollution by counting stars in the sky, while discovering the level of light pollution in their own neighbourhood. Participants used a cardboard tube (e.g. a kitchen paper roll), a bit of string, tape and a protractor to construct a measuring tube. They then observed the night sky through the tube and counted visible stars in a number of directions. Directions were determined by means of a compass, and all results were reported via a smartphone app. The project was run as part of ForskarFredag – the Swedish events during the European Researchers' Night.

The Star-Spotting Experiment was created by the non-profit organisation VA (Public & Science), the National Resource Center for Physics Education (NRCF), Lund University, Kristianstad University, the Swedish National Space Agency, and the two science centres House of Science (Vetenskapens hus) and Umevatoriet, Sweden. The project was run in collaboration with Fundación Descubre, Esciencia, La Palma Centre and Fundación madri+d in Spain, University College Cork and Trinity College in Ireland and Natural History Museum in London, UK.


The aim of the Star-Spotting Experiment was to measure and map light pollution at a local level, by means of an easy-to-use method and a smartphone app.

Needed equipment

• A simple cardboard tube, such as a kitchen or toilet paper roll. It is important that you know the length and diameterof the tube.
• A compass, either on a mobile app or a classic analogue compass.
• An Internet connection and a computer or the Star-Spotting Experiment app, which is available for both mobile and tablet.
• Protractor, string and a weight (e.g. a nut).
• Information about what time the sun sets where you are. There are apps and websites which provide this information (eg the Sunrise Sunset Lite app). 

Completed from 31/01/2019 until 15/03/2020
Astronomy Education Light Pollution
Science Topics
Astronomy & Space Education
Participation tasks
Data Entry Geolocation Observation
Macro-regional Europe
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