Atacama Desert, Chile — It takes a moment for the eyes to adjust. A faint spark is visible in the darkness; Then another, brighter. Soon, stars, planets, and entire constellations come into view. In no time, an entire galaxy stretches across the sky, visible to the naked eye.
The night sky in Chile’s Atacama Desert seems endless. Agreed driest place on earthIts darkness is also one of the clearest windows into the universe.
A rare combination of dry climate, high altitude and, importantly, isolation from urban light pollutionmakes Atacama an unrivaled center for world-class astronomy and home to the world’s largest land-based astronomical projects.
“The conditions of the Atacama Desert are unique in the world,” said Chiara Mazzuchelli, president of the Chilean Astronomical Society. “There are more than 300 clear nights per year, meaning no clouds and no rain.”
But the world’s darkest sky may be in danger.
Last year, the desert became a battlefield A green energy complex is being proposed between scientists and an energy firm just kilometers (miles) away. Paranal Observatory. Managed by the European Southern Observatory, ESO, the site is also the future home of the most powerful optical telescope ever built.
Although the energy project was canceled in January after a strong appeal from astronomers, physicists and Nobel laureates, it highlighted deep concerns that existing sky protection laws are lax, outdated and vague. Since then, several environmental regulations have been reviewed, including those targeting astronomical areas protected by Chile’s Ministry of Science.
“We are working to ensure that the new criteria are strict enough to have no impact on astronomical areas,” said Daniela Gonzalez, director of the Cielos de Chile Foundation, a nonprofit founded in 2019 to protect the quality of Chile’s night sky.
The Associated Press spent three days visiting paralegal facilities Heart of the so-called photon valley. In this high-altitude corridor, multiple observatories operate simultaneously using some of the most sophisticated equipment ever engineered.
“Many of these large facilities are located in Chile, and ESO’s telescopes in particular are some of the most powerful astronomical facilities on the planet,” said Itziar de Gregorio-Monsalvo, the intergovernmental organization’s representative in Chile.
Paranal is one of about 30 astronomical sites in northern Chile, most of which are managed by international organizations. Every year, the Atacama Desert attracts thousands of astronomers and scientists from around the world to investigate the origins of the universe.
“We are lucky to be here,” said Julia Bodensteiner, assistant professor at the University of Amsterdam, noting that the chances of being selected as a visiting astronomer at Paranal are only 20% to 30%.
Walking across the rocky, rugged terrain of the Atacama is no easy task. At altitudes above 3,000 meters (10,000 ft), oxygen becomes a luxury, while scorching days give way to increasingly cold nights. But for space observation and exploration, this desert of more than 105,000 square kilometers (40,500 square miles) is the perfect place.
The Atacama’s extraordinary conditions have enabled some of the most ambitious astronomical projects ever undertaken, such as the Extremely Large Telescope, ELT – a $1.5 billion effort by ESO scheduled for completion in 2030.
With 798 mirrors and a light-collecting area of approximately 1000 square meters (a quarter acre), the ELT will be 20 times more powerful and 15 times brighter than today’s leading telescopes. NASA’s Hubble Space Telescope.
All data compiled These observatories play a fundamental role not only for life on Earth, but also for the prospects for its evolution beyond our planet. Conservation of these research sites is necessary.
With ELT, ESO astronomer Lucas Bordon said, “We should be able to see Earth-like planets in what we call the habitable zone, so basically planets that are candidates for life.”
Twenty years ago, the Atacama Desert was “an ocean of darkness,” recalled Eduardo Unda-Sanzana, director of the astronomy center at the University of Antofagasta. “It was just you and the universe.”
However, in the last few years The landscape has changed considerably.
Driven by urban sprawl, industrial development and the advent of mining and wind farms, the desert has become an iconic zone where it is not always easy to reach balance.
In Paranal, specialists live like shrews in an underground habitat designed to keep their presence virtually unknown. Windows must remain covered, hallways must remain dark, and any outdoor activity must be guided by flashlight only. Even the slightest light can interfere with telescopes.
Last year the announcement of an impending green energy project shocked the international scientific community. Experts pressured officials to protect Chile’s night sky from the proposed site, which was to be built just 10 kilometers (6 mi) from Paranal.
The case raised concern due to its effects, such as increased light pollution, microscopic vibrations and dust, as well as greater atmospheric turbulence. These conditions would make astronomical activities impractical.
“If you put the ELT next to a city, it doesn’t matter if it’s 40 meters tall. It’s exactly the same as a small telescope,” Gregorio-Monsalvo said.
Although the company canceled the project in late January, scientists have warned that without new, updated regulations, similar projects could be proposed at any time.
“Despite all the media hype about 2025, we find ourselves exactly where we were last year,” said Unda-Sanzana, who is also part of the ministerial advisory commission that made recommendations to the Chilean government after the recent incident.
There is no dearth of examples. The first International Heliophysics Observatory in Chile – a major solar station operated by the US Smithsonian Institution in the early 20th century – was forced to cease operations in 1955 due to environmental pollution caused by the expansion of mining activity in the area.
“We have 70 years to learn from history and avoid repeating the same mistakes,” Unda-Sanzana said.
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