ATACAMA DESERT — Chile's science ministry is reviewing environmental regulations targeting protected astronomical zones in the Atacama Desert following the January cancellation of a proposed green power complex near the Paranal Observatory. The cancellation followed an appeal from astronomers, physicists and Nobel laureates after an energy firm last year proposed the complex at a site 10 kilometers from Paranal.

"We are working to ensure the new criteria are strict enough to guarantee that there will be no impact on astronomical areas," said Daniela González, director of the Cielos de Chile Foundation. The Atacama Desert, the driest place on Earth, covers more than 105,000 square kilometers and offers some of the clearest views of the universe due to its dry climate, high altitude and isolation from urban light pollution.

It is home to the world's largest ground-based astronomical projects, with Paranal one of nearly 30 astronomical sites in northern Chile, most managed by international organizations. Observatories operate at altitudes above 3,000 meters where oxygen is scarce and temperatures range from hot days to cold nights. Every year, the desert draws thousands of astronomers and scientists from around the world to investigate the origins of the universe.

Specialists at Paranal live in an underground residence designed to keep their presence almost undetectable, with windows covered, dark hallways and movement guided only by flashlight. Increased light pollution, micro-vibrations, dust and greater atmospheric turbulence from the proposed energy project would have made astronomical activities unviable, according to the appeal.

Among the facilities at Paranal is the Extremely Large Telescope (ELT), a $1.5 billion project by the European Southern Observatory scheduled for completion in 2030. The ELT will have 798 mirrors and a light-gathering area of nearly 1,000 square meters, and it is designed to be 20 times more powerful than current leading telescopes and 15 times sharper than NASA's Hubble Space Telescope.

"Many of these large facilities are located in Chile, and ESO's telescopes in particular are the most powerful astronomical facilities on the planet," said Itziar de Gregorio-Monsalvo, representative in Chile of the European Southern Observatory. "If you place the ELT next to a city, it doesn't matter that its diameter is 40 meters long. It's just the same as having a tiny telescope."

The landscape of the Atacama Desert has changed due to urban sprawl, industrial development, mining and wind farms. A heliophysics observatory operated by the U.S. Smithsonian Institution in Chile shut down in 1955 due to environmental pollution from mining expansion.

"Twenty years ago, the Atacama Desert was an ocean of darkness. It was just you and the universe," said Eduardo Unda-Sanzana, director of the Astronomy Center at the University of Antofagasta. He is part of a ministerial advisory commission that recently delivered recommendations to Chile's government. "We've had 70 years to learn from history and avoid repeating those same mistakes," he said.