Cerro Paranal is a mountain more than 2500 meters high in the Coastal Cordillera in the Atacama desert, in Chile. Up here, in absolute darkness, there is a beautiful observatory, which includes the Very Large Telescope (VLT) of the European Southern Observatory (ESO, from English European Southern Observatory), the largest in the world.
All was well, until the news arrived that an agreement could soon be approved there renewable energy project. Good, but not very well, because it could affect that thick darkness of vital importance for the Observatory.
Exactly in these parts, in fact, the US energy company AES Energy wants to build a large complex for the renewable hydrogen production a few kilometers from the top of Mount Paranal. Which would mean, according to astronomers, that the most precious place for observing the sky in the world could be ruined by strong light pollution.
In fact, Mount Paranal is one of the last places on Earth free from urban and industrial light pollution. Thanks to the unique geography of the Andes mountain range, the star-studded night sky above the summit is perfectly clear for more than 11 months of the year, providing the perfect conditions for the most challenging astronomical research.
The VLT is one of the most sensitive sky observation instruments there is, capable of observing the most intriguing objects in the universe. The high-precision observatory consists of four 8.2-meter-wide telescopes acting as one, and has shed light on some of the most mysterious phenomena known to humanity.
But the observation potential of this astronomical powerhouse will be significantly reduced if the hydrogen project, the so-called INNA, receives the green light, explains Xavier Barcons, Director General of ESO.
So far, the VLT has allowed astronomers to trace orbits of stars in the immediate vicinity of the black hole at the center of the Milky Way, take the first-ever image of a planet outside the solar system, and discover the elusive cosmic web that it extends throughout the cosmos.
It’s the darkest place we’ve ever installed an observatory in the world, by a wide margin, astronomers still say, and the light pollution predicted by the INNA project could undo all the progress made, causing the ability to observe about 30% of the faintest galaxies.
The INNA project, a 3,021-hectare industrial park worth $10 billion, is expected to consist of three solar parks, three wind farms, a battery energy storage system and hydrogen production facilities.
ESO estimates that the complex will lose as much light pollution as a city with a population of around 20,000, and parts of the industrial park could extend up to 5 kilometers to ESO’s telescopes, and any possible further expansion would further worsen the impacts on the sky night of the Paranal.
We are at the point of starting to see details of exoplanet atmospheres, but if the sky gets brighter, we may no longer be able to see those details, concludes Barcons.
