Light pollution is increasing rapidly and in some places the number of stars visible to the naked eye in the night sky has more than halved in less than 20 years, according to a study released Thursday.
The researchers whose findings were published in the journal Sciencessaid the increase in light pollution — the glow of the sky — that they found was much greater than that measured by satellite observations of Earth at night.
To study the change in global sky brightness from artificial light, the researchers used stellar observations from 2011 to 2022 made by more than 51,000 “citizen scientists” around the world.
Participants in the “Globe at Night” project run by the US National Laboratory for Optical and Infrared Astronomy were given star maps and asked to compare them with night sky in their site.
The change in the number of reported visible stars was the equivalent of 9.6 percent per year Annual increase The brightness of the sky, averaged the locations of the participants, the researchers said.
Over the course of 18 years, due to such a change in star brightness, a site with 250 visible stars would see that number drop to 100.
more than with the naked eye The star observations came from Europe and the United States, but there was also good participation from Uruguay, South Africa and Japan, said Christopher Kyba, one of the study’s authors.
“The global trend in celestial glow that we measure is likely to reduce the trend in countries with the most rapid increases Economic growthBecause the rate of change of light emission is higher there.”
The study coincided with the replacement of many of the exterior lights with light emitting diodes (LEDs), but the effect on celestial glow from the transition to LEDs is not clear, the researchers said.
“Some researchers expected it to be beneficial; others, it might be detrimental because of spectral changes or the bounce effect, whereby the higher luminous efficacy of LEDs leads to more or less brightly installed lamps or longer operating hours,” they said.
According to the study, the global market share of LEDs for new general lighting has grown from less than one percent in 2011 to 47 percent in 2019.
The researchers said: “Stellar visibility is rapidly deteriorating, despite (or perhaps because of) the introduction of LEDs in outdoor lighting applications.
“Current lighting policies do not prevent increases in celestial glow, at least on the continental and global scales.”
face the universe
Kiba, a physicist at the German Research Center for Geosciences, told AFP that while the team was able to assess the erosion of star vision by celestial glare, not much research had been done on it. environmental impact.
“There’s a lot of research out there Noor It shines directly on animals and plants. But it is really difficult to experiment with the effect of heavenly glow.
“You wouldn’t do anything like turn off New York City and see what happens on the East River.”
flag aside, light pollution It has changed the nature of the night sky.
to all human historyWhen people went out at night, they were kind of facing the universe, at least on clear, moonless nights,” Kiba said.
He said, “You’re walking outside and there are the stars, there’s the Milky Way. They’re out there and shining on you.”
“And now this is a really extraordinary experience,” he said. “It’s definitely us as people who don’t have this experience that used to be so universal, that makes a difference for us as people.”
The Globe at Night campaign is hosting an interactive data map at globepatnight.org and is looking for volunteers to collect more observations in 2023.
Christopher CM Kyba, citizen scientists who reported rapid global declines in stargazing from 2011 to 2022, Sciences (2023). DOI: 10.1126/science.abq7781. www.science.org/doi/10.1126/science.abq7781
More information on “Globe at Night” can be found here. here.
© 2023 AFP
the quote: Star visibility eroding rapidly as the night sky gets brighter: Study (2023, January 22) Retrieved January 22, 2023 from https://phys.org/news/2023-01-star-visibility-eroding-rapidly-night.html
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