Critical Assessment Alleges Energy Project Destruction for Astronomy Heaven on Earth
In the heart of the Atacama Desert in northern Chile, one of the world's premier locations for ground-based astronomy, a planned industrial megaproject named INNA poses a significant threat. The project, intended for site testing and astronomical observations in close proximity to established facilities like the Paranal Observatory and ESO's telescopes, could limit the ability to make key astronomical discoveries and compromise Chile's strategic advantage in this area.
According to a report released recently, should the INNA project be approved, the value of the telescopes installed or planned by ESO would be substantially decreased. These losses are manyfold and not recoverable world-wide. The report's technical summary can be found here.
Detailed analyses show that the INNA project, if executed at the currently baselined site, would significantly and negatively impact the performance of all ESO's telescopes at the site. Due to proximity, the mitigation of these effects is impossible. The project could cause artificial light contamination, increase ground vibrations, increase atmospheric turbulence, and contaminate optical surfaces, including telescope mirrors and lenses.
The proposed INNA project could cause light pollution at CTAO-South to increase by at least 35% and more than 50%, hindering scientists' abilities to observe and understand the universe. A "location with 250 visible stars would see that number reduce to 100 visible stars over the same period," according to a study published in Science. The report states that a 1% artificial light contamination could mean one polluted photon for every 100 natural sky photons, indistinguishable from a photon coming from a faint object at the edge of the Universe as detected by the most powerful telescope ever built, like the ESO's Extremely Large Telescope (ELT), the successor to VLT.
The disturbances from the INNA project seriously threaten the current and long-term viability of Paranal as a world-leader in astronomy. The limits of ground vibration on the VLT interferometer and the ELT itself would likely be exceeded by the INNA project, and the wind turbines would produce similar turbulence in the air to that of wind farms, inhibiting the observatory's ability to see the skies. The project could limit the ability to directly detect Earth-like exoplanets, observe faint galaxies, and monitor asteroids that could cause damage to our planet.
ESO authorities are not up in arms about the INNA project in itself. The proximity is the problem. The observatory's director general, Xavier Barcons, states that Chile should not have to make a choice between hosting the most powerful astronomical observatories and developing green-energy projects; both are declared strategic priorities by the country and are fully compatible if the different facilities are located at sufficient distances from one another.
A full technical report on the potential impacts of INNA on Paranal will be submitted to authorities this month, and made public before April 3. As of now, the report does not specify whether parties have come to a mutually beneficial decision to relocate the INNA complex to save Paranal's pristine skies and protect astronomy for future generations, as suggested by de Gregorio-Monsalvo.
The graph below shows how dark Paranal's skies are relative to the observing conditions of other famous observatories.
Light pollution is a growing threat to ground-based observatories, with data showing the night sky got 9.6% brighter each year from 2011 to 2022, on average. Martin Aubé, an expert on sky brightness, suggests that light pollution from an entity like INNA would be exacerbated by cirrus cloud cover, which would reflect artificial light, worsening the problem.
Certainly, these findings underscore the importance of carefully considering the location of large-scale projects, especially those that could potentially impact the future of astronomy and our understanding of the universe. The decision regarding the INNA project and its potential impact on Paranal's pristine skies is one that will have implications far beyond Chile's borders.
