Astronomers have won the latest battle over dark skies, but the global conflict continues

"Last week AES Andesa subsidiary of the AES Corporation, an American energy companyannounced it had scrapped its plans for a sprawling, city-size renewable energy project in Chile's Atacama Desert. The Atacama offers some of the world's darkest, clearest skieswhich is why it also hosts several of Earth's most important ground-based telescopes, including those of the European Southern Observatory's (ESO's) Paranal Observatory, which could've been within a mere five kilometers of the green-energy facility, according to earlier plans."

"An ESO study had predicted that the project, called INNA (Integrated Energy Infrastructure Project for the Generation of Hydrogen and Green Ammonia), would increase light pollution by at least 35 percent for Paranal's Very Large Telescope, a set of four interlinked 8.2-meter observatories at the forefront of astronomical research. The study also found that INNA's operations would increase atmospheric turbulence, muddying what would otherwise be sharp images of the heavens from nearby telescopes."

"The decision comes after a year of backlash from astronomers who have been relying on the telescopes under Chile's world-class skies. They feared that light pollution from the project would ruin their celestial views. In early 2025, as the potentially dire impacts of the project became more widely known, one astronomerMaria Teresa Ruiz of the University of Chilebegan an oppositional letter-writing campaign to news organizations and scientific journals."

AES Andesa, a subsidiary of AES Corporation, canceled plans for the INNA renewable energy project in Chile's Atacama Desert. The project would have been near ESO's Paranal Observatory and threatened some of the world's darkest skies. An ESO study predicted INNA would increase light pollution by at least 35% for Paranal's Very Large Telescope and raise atmospheric turbulence, degrading image quality. Astronomers mounted a year-long campaign of objections, including letter drives by Maria Teresa Ruiz and visits involving Nobel laureate Reinhard Genzel and Germany's president. Concerns about protecting ground-based astronomical observations drove the decision to abandon the project.

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