Light Pollution Causing Stars To Disappear From The Night Sky, Warn Researchers

The stars in the night sky are disappearing due to rapid increases in light pollution, according to data collected by scientists from around the world. Due to the same, the number of stars visible to the naked eye in the night sky is being reduced by more than half in some places in less than 20 years, a study based on the data has said.

As a consequence of artificial light, which causes light pollution, sky brightens up to 10 per cent per year. This implies that a significant portion of the once-visible stars are now obscured to astronomers and the general public. The study is published in the journal Science and was done from 2011 to 2022.

Light pollution is obstructing those stars and is expanding far more quickly than scientists had realised. It could have adverse effects on the environment, the biological systems of humans and animals, as well as the visibility of the night sky, as per the research. Skyglow, the background shimmer of photons released by streetlights, billboards, storefront and numerous other human sources, is the most prevalent type of light pollution. 

About 51,000 "citizen scientists" from all over the world provided star observations from 2011 to 2022, which the researchers used to analyse how the brightness of the entire planet changed as a result of artificial light. The National Optical-Infrared Astronomy Research Laboratory in the US provided star maps to participants in the "Globe at Night" project, asking them to contrast them with the local night sky.

According to the data, the brightness of the sky has increased by 9.6 per cent annually. Previous estimates based on data from satellites noted that the brightness was only increasing by two per cent.

Christopher Kyba, a physicist at the GFZ German Research Centre for Geosciences, said, "It's pretty shocking. Even worse than I had worried." According to him, if the trend continues, by the age of 18, children born today in a light-polluted location, who can currently see roughly 250 stars, will only be able to see 100 stars due to skyglow.

The researchers note that the global trend in skyglow underestimates the trend in countries with the most rapid increases in economic development. This is because the rate of change in light emission is highest there.