The number of stars that people can see with the naked eye has reduced dramatically over the last decade.
The cause is "Skyglow" from artificial lighting - the brightness of that glow has increased every year since 2011.
It is the conclusion of 12 years of amateur astronomers and citizen scientists going out at night to count the stars.
The change in stars' visibility that people reported - by submitting their star counts to an online project called Globe at Night - was equivalent to an almost 10% annual increase in sky brightness every year.
That means, the scientists say, that a child born in an area where 250 stars were visible, would probably see fewer than 100 stars in the same location 18 years later.
According to a 2022 study by the European Space Agency the relatively low cost of LED lighting is also contributing to the problem.
The agency described this as a "lighting paradox", explaining: "While the LED lighting revolution promised to reduce energy consumption and improve human vision at night, overall [light pollution has] increased. Paradoxically, the cheaper and better the lighting, the higher society's addiction to light."
