The star-laden night sky could become a thing of the past within 20 years due to light pollution, according to scientists.
In 2016, astronomers reported that the Milky Way was no longer visible to a third of humans and now, with worsening light pollution, scientists have warned that major constellations will be indecipherable in the next two decades, a report in The Guardian said.
Extensive use of light-emitting diodes (or LEDs) and other forms of lighting are brightening the night sky at an increasing rate, scientists have reported. Excessive use of external lighting, street illumination, advertising, and sporting venues are hindering people’s view of the stars. The increasing light pollution over the years has put humanity's view of the cosmos at risk.
Today, many young people in cities are growing up without seeing stars. Speaking to The Guardian, Martin Rees, the British astronomer royal said: “The night sky is part of our environment and it would be a major deprivation if the next generation never got to see it, just as it would be if they never saw a bird’s nest.” He further added that one doesn't have to be an astronomer to care about this. “I am not an ornithologist but if there were no songbirds in my garden, I’d feel impoverished.”
Rees is a founder of the All-Party Parliamentary Group for Dark Skies, which published a report on light pollution in 2020, elaborating on 10 policy recommendations to address the light pollution in the UK which threatens dark sky preservation.
A new study published in January 2023 involving more than 50,000 observations of stars by citizen scientists revealed that the night sky was about 10 percent brighter, on average, every year from 2011 to 2022. The study was published in the journal Science.
This means, children born where 250 stars are visible at night today would only be able to see about 100 by the time they reach the age of 18, physicist Christopher Kyba, of the German Centre for Geosciences, explains in The Guardian’s report.
One of the major factors is LED lights, according to scientists. Although LEDs are energy-efficient, they emit more short-wavelength blue light, which scatters off particles in the atmosphere, causing more sky glow. According to the Guardian report, it’s important to remember simple solutions: ensuring outdoor lights are carefully shielded and pointing downwards, have limits on their brightness, and are not predominantly blue-white but have red and orange components.
“People should consider that this does have an impact on our lives. It’s not just astronomy. It impacts our health. It impacts other animals who cannot speak for themselves,” astronomer Connie Walker of the National Optical-Infrared Astronomy Research Laboratory told Science News.