A child born in a place where 250 stars can be seen in the night sky today will only be able to see 100 stars when the child turns 18.
People around the world see fewer and fewer stars in the night sky. The change in the visibility of the stars can be explained by an increase in the brightness of the sky of 7-10% per year. This is a worrying statistic since future generations will hardly know what stars in the night sky look like at the pace we are moving forward. Even more worrying is that the rate of light pollution is changing faster than suggested by satellite measurements of artificial light emissions on Earth. This was the conclusion reached by a group of astronomers in their paper published in Science. The study was led by Christopher Kyba, from the GFZ German Research Center for Geosciences and the Ruhr-Universität Bochum, with colleagues from the GFZ and the NOIRLab of the NSF (National Science Foundation) in the United States.
How do they know?
The researchers came to this conclusion thanks to more than 50,000 naked-eye observations made by citizen scientists around the world between 2011 and 2022 as part of the “Globe at Night” citizen science project. The results show that citizen science data is an important complement to previous measurement methods. We know for a fact that over much of the Earth’s surface, the sky continues to glow with artificial twilight long after sunset. In fact, there are only so few places left where light pollution does not affect observations of the night sky or astrophotography. This “sky glow” is a form of light pollution that has severe effects on the environment and therefore needs to be investigated with greater detail.