The Atacama Desert, known for its exceptional stargazing conditions, faces threats from a proposed hydrogen production facility near the Paranal Observatory. Experts warn that the facility could introduce significant light pollution, jeopardizing astronomical research and the visibility of celestial bodies. While the project claims environmental benefits, the European Southern Observatory emphasizes the need to balance energy development with the preservation of this vital astronomical site, highlighting the detrimental impact of light pollution on scientific discovery.
The Wonders of the Atacama Desert
The Atacama Desert stands out as the driest location on Earth and serves as one of the rare spots where the Milky Way is visible to the naked eye. Untouched by light pollution, this expansive desert in northern Chile provides unparalleled sky quality, making it a prime location for astronomical research.
Astronomers are in a unique position to explore the cosmos, which is why some of the world’s most advanced and costly telescopes have been established in this region. The clarity of the night sky here has made it a coveted destination for scientists eager to unlock the mysteries of the universe.
Threats to Astronomical Observations
However, this pristine environment is now under threat, according to experts from the European Southern Observatory (ESO). The American firm AES Energy has proposed the construction of a green hydrogen and ammonia production facility in Taltal, located about ten kilometers from the renowned Paranal Observatory, home to the Very Large Telescope (VLT) and the upcoming Extremely Large Telescope (ELT).
The announcement has sparked outrage among ESO teams at Paranal. This observatory, inaugurated in 1999 at a height of 2,600 meters, was chosen for its ideal conditions for astronomical observation, including its arid climate and minimal cloud cover. The anticipated light pollution from this industrial complex, which will span over 3,000 hectares, poses a serious risk to the effectiveness of the region’s observatories, including the ALMA radio telescope and La Silla optical telescope.
Itziar de Gregorio, a representative of ESO in Chile, expressed concerns about the implications of the hydrogen plant project. “We have constructed the largest and most powerful telescopes in the optimal location for astronomy, allowing researchers worldwide to uncover what was previously unseen. The light pollution from this project not only obstructs research but also diminishes our collective understanding of the universe,” she stated in a press release urging for the project’s cancellation.
A study by the ESO indicates that the light pollution from the proposed facility could increase the brightness of the night sky above the VLT by 35%. This heightened brightness would severely limit the ability to detect Earth-like exoplanets, observe faint galaxies, and track potentially hazardous asteroids. De Gregorio warns that this initiative jeopardizes “one of the most significant astronomical treasures on the planet.”
The nearby Cherenkov Telescope Array (CTA) observatory, currently under construction just five kilometers from the proposed hydrogen plant, is also at risk, along with the European Extremely Large Telescope (E-ELT), which will be the largest telescope for visible and infrared light upon completion by the end of the decade.
AES Energy emphasizes the project’s environmental benefits, including green hydrogen and ammonia production, as well as the integration of solar and wind energy, aligning with Chile’s commitment to enhancing renewable energy sources. In a statement to Space.com, the company asserted that the project will adhere to “the strictest lighting standards,” as mandated by the Chilean Ministry of the Environment.
A comprehensive report on the project’s impact regarding light pollution is expected to be submitted to Chilean authorities soon. The ESO and its member states are in favor of the decarbonization of energy but believe that Chile should not have to choose between hosting leading astronomical observatories and advancing green energy initiatives. Both can coexist if properly distanced, argued ESO’s director general, Xavier Barcons. Yet, there is no certainty that this position will prevail.
As light pollution continues to encroach, a recent study published in 2023 in the journal Science suggests that the number of stars visible to the naked eye could be cut in half in certain areas within two decades. For instance, a child born today in a region with visibility of 250 stars may only be able to see around 100 by age 18. This development serves as a stark reminder of humanity’s impact on nature. As astrophysicist Hubert Reeves famously said, “Man is waging a war against nature. If he wins, he is lost.” It is a sentiment that Chilean authorities should heed.