World's darkest and clearest skies at risk from industrial megaproject
On December 24th, AES Andes, a subsidiary of the US power company AES Corporation, submitted a project for a massive industrial complex for environmental impact assessment. This complex threatens the pristine skies above ESO's Paranal Observatory in Chile's Atacama Desert, the darkest and clearest of any astronomical observatory in the world.
The industrial megaproject is planned to be located just 5 to 11 kilometers from telescopes at Paranal, which would cause irreparable damage to astronomical observations, in particular due to light pollution emitted throughout the project's operational life. Relocating the complex would save one of Earth's last truly pristine dark skies.
An irreplaceable heritage for humanity
Since its inauguration in 1999, Paranal Observatory, built and operated by the European Southern Observatory (ESO), has led to significant astronomical breakthroughs, such as the first image of an exoplanet and confirming the accelerated expansion of the universe. The Nobel Prize in Â鶹ÒùÔºics in 2020 was awarded for research on the supermassive black hole at the center of the Milky Way, in which Paranal telescopes were instrumental.
The observatory is a key asset for astronomers worldwide, including those in Chile, which has seen its astronomical community grow substantially in the last decades. Additionally, the nearby Cerro Armazones hosts the construction of ESO's Extremely Large Telescope (ELT), the world's biggest telescope of its kind—a revolutionary facility that will dramatically change what we know about the universe.
"The proximity of the AES Andes industrial megaproject to Paranal poses a critical risk to the most pristine night skies on the planet," said ESO Director General, Xavier Barcons.
"Dust emissions during construction, increased atmospheric turbulence, and especially light pollution will irreparably impact the capabilities for astronomical observation, which have thus far attracted multi-billion-Euro investments by the governments of the ESO Member States."
The unprecedented impact of a megaproject
The project encompasses an industrial complex of more than 3000 hectares, which is close to the size of a city, or district, such as Valparaiso, Chile or Garching near Munich, Germany. It includes constructing a port, ammonia and hydrogen production plants and thousands of electricity generation units near Paranal.
Thanks to its atmospheric stability and lack of light pollution, the Atacama Desert is a unique natural laboratory for astronomical research. These attributes are essential for scientific projects that aim to address fundamental questions, such as the origin and evolution of the universe or the quest for life and the habitability of other planets.
A call to protect the Chilean skies
"Chile, and in particular Paranal, is a truly special place for astronomy—its dark skies are a natural heritage that transcends its borders and benefits all humanity," said Itziar de Gregorio, ESO's Representative in Chile. "It is crucial to consider alternative locations for this megaproject that do not endanger one of the world's most important astronomical treasures."
The relocation of this project remains the only effective way to prevent irreversible damage to Paranal's unique skies. This measure will not only safeguard the future of astronomy but also preserve one of the last truly pristine dark skies on Earth.
Provided by ESO
