Light pollution stronger than expected
Fewer and fewer stars to be seen in the night sky
Observing stars in the night sky becomes more difficult. In some places, in less than 20 years, only half as many stars will be visible to the naked eye in the night sky, according to a study published Thursday in the journal Science.
Published: 18 minutes ago
A large part of the world’s population lives under a more or less light-polluted sky.
The reason for this is light pollution from artificial light, which is greater than previously assumed based on satellite images.
The study is based on the observations of around 51,000 so-called citizen scientists, mainly in the USA and Europe, in the years 2011 to 2022. They reported the number of visible stars in their place of residence. From this information, the scientists calculated that light pollution increased by an average of 9.6 percent per year. If it continues to increase at this rate, a place where you can see 250 stars today would only be able to see 100 in 18 years.
Existing policies do not prevent light pollution
During the period of the study, the outdoor lighting was switched to LED lamps in many places. According to the researchers, it is still unclear how LEDs affect light pollution.
“Star visibility has deteriorated rapidly despite – or perhaps because of – the use of LEDs for public lighting,” the scientists noted. They conclude that “existing lighting guidelines do not prevent light pollution”. It is also unclear and difficult to measure how increasing light pollution is affecting animals and plants.
Stars count for science
The illumination of cities and streets at night has changed the character of the night sky. «In the past, when people went outside at night, they were confronted with the cosmos in a certain way. You saw the stars, the Milky Way,” said study author Christopher Kyba from the Geoforschungszentrum in Potsdam of the AFP news agency. “And now this is a really unusual experience. It certainly makes a difference for us as humans when we stop having that universal experience.”
Research on light pollution continues. The international Globe at Night campaign is looking for volunteers to count the visible stars for science this year.