SANTIAGO, Chile (AP) — Chile’s Atacama Desert is one of the darkest places on Earth and a crown jewel for astronomers who flock to this inhospitable stretch of desert along the Pacific coast to study the origins of the universe.
A rare confluence of factors makes the Atacama an ideal location for some of the world’s largest ground-based astronomy projects—a dry climate, high altitude, and, most importantly, an absence from the light pollution of civilization.
“It’s the perfect cocktail for astronomy,” said Daniela González, executive director of the Chilean Sky Foundation, a nonprofit dedicated to preserving the quality of the country’s night skies.
But on Tuesday, a group of top scientists warned in an open letter to the Chilean government that this might not last long.
A private company is stepping up plans to build a giant renewable energy complex near one of the most productive astronomical facilities on Earth, the Paranal Observatory, which is operated by the international consortium of the European Southern Observatory (ESO).
In the letter, 30 internationally renowned astronomers, including Reinhard Genzel, winner of the 2020 Nobel Prize in Astrophysics, stated that the project poses an “imminent threat” to humanity’s ability to study the universe and unlock more unknown things.
“The damage will extend beyond Chile’s borders, affecting the scientific community around the world, which relies on Paranal’s observations to study everything from planet formation to the early universe,” the letter reads.
“We believe that economic development and scientific progress can and must coexist to the benefit of all Chilean people, but not at the irreversible cost of one of Earth’s unique and irreplaceable windows on the universe.”
Scientists have been urging the Chilean government to relocate the hydrogen fuel production plant since AES Andes, a division of US multinational AES Corporation, unveiled the plan a year ago.
In response to a request for comment, AES said its own technical studies showed the project would be fully compatible with astronomical observations and comply with the Chilean government’s strict regulations on light pollution.
“We encourage trust in the strength of the country’s institutions, which for decades have guaranteed certainty and environmental protection across multiple production sectors,” the company said.
The plan, which is still undergoing environmental review, calls for 3,000 hectares (7,400 acres) of wind and solar farms, a desalination plant and a new port.
This means not only a huge increase in light pollution, but also an increase in new dust, ground vibrations and atmospheric turbulence, all of which can blur stars and cause them to twinkle. Experts say all this – just 3 kilometers (1.9 miles) from the Paranal Observatory’s high-powered telescope – will disrupt views of key astronomical targets and could hinder scientific progress.
“In the world’s most ideal locations for astronomy, stars do not twinkle. They are so stable that even the smallest artificial turbulence can disrupt these features,” said Andreas Kaufer, ESO’s director of operations. The agency assessed that the AES project would increase light pollution by 35 percent.
“If the sky is made brighter by the artificial light around us, we can no longer make these observations. They are lost. And since we have the largest, most sensitive telescopes in the best places in the world, if they are lost to us, they are lost to everyone.”
While the controversy may be specific to Chile, which hosts 40% of the world’s astronomical infrastructure, the project reflects a broader tension between natural darkness and industrialization, as light pollution causes the night sky to brighten by about 10% each year, torn in countless countries.
“The major observatories have been driven into remote areas, and now they’re essentially being driven into some of the last dark-sky locations on Earth, like the Atacama Desert, the peaks of Hawaii, the areas around Tucson, Arizona,” said Ruskin Hartley, executive director of Dark Sky International, a Tucson-based nonprofit founded by astronomers.
“Now all of these are at risk of encroachment by development and mining. It’s happening everywhere.”
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Debray reported from Buenos Aires, Argentina.
