In the Atacama desert, the world’s driest non-polar region, the sky illuminates spectacularly at sunset. Situated 130km south of Antofagasta, comets burn radiantly, and the night sky is adorned with flawless trails of stars and nebulae. The region’s darkness is so profound that Indigenous peoples found shapes of animals and ancestors among the stars, leveraging the perfect dark skies. These are the darkest and clearest skies globally, which have positioned Chile as the world’s leading astronomical hub. However, this unique asset faces imminent threats.
AES Andes has proposed the Inna project, Chile’s first industrial-scale green hydrogen and ammonia processing plant. The facility, spread over 3,000 hectares along with a port, transport links, and three solar power plants, will produce solar and wind energy, feeding excess energy into the national grid. The proposed site is disturbingly close to one of Chile’s crucial observatories, raising serious concerns among astronomers.
Criticisms from Chile’s environmental regulator regarding the project’s location did not prevent a $10 billion project deadline from passing, highlighting the ongoing threat to Chile’s observatories. The astronomical community firmly opposes the plan, arguing that the project’s scale and the necessity of night-time illumination could severely impact readings. Even the dust and atmospheric turbulence from the planned wind turbines pose significant concerns for scientists.
Dr. Fabio Falchi emphasizes the importance of locations with clear nights, low atmospheric interference, and dark skies for ground-based astronomy, identifying Paranal Observatory and nearby Cerro Armazones as prime sites for such research. The Very Large Telescope (VLT) at Paranal and the under-construction Extremely Large Telescope (ELT) on Cerro Armazones represent significant advancements in astronomical observation, with the latter expected to revolutionize the search for Earth-like exoplanets upon completion.
The proposed facility could compromise the quality of data collected by the ELT, potentially reducing its effectiveness to that of a much smaller telescope due to light pollution. The European Southern Observatory, which operates the Paranal Observatory, is committed to preserving the quality of Chile’s skies for astronomical observation, underscoring the critical need for darkness and atmospheric stability.
Concerned about the site’s proximity to the VLT and the potential long-term effects on their research capabilities, astronomers and regulatory bodies are advocating for a reevaluation of the project’s location. The debate highlights the tension between industrial development and the preservation of unspoiled, dark skies, a balance critical for the future of astronomical research in Chile.
Source: https://www.theguardian.com/world/2025/mar/04/chile-stargazing-night-sky
