Light pollution threatens fleet of world-class telescopes in Atacama Desert

A massive green hydrogen plant proposed for construction in Chile could increase Featherweight pollution at one of the world’s most powerful telescopes by at least one-third, says the European Southern Universe lab (ESO), the consortium that operates the Stargazer’s tool and will either host or operate others being built nearby.

An ESO analysis released on Monday Discovered that Featherweight pollution would increase by at least 35% at the Very Large Stargazer’s tool (VLT) ― one of the most advanced optical telescopes in the world ― and by at least 55% at the southern array of the Cherenkov Stargazer’s tool Array Universe lab (CTAO), which is now under construction and will be the largest ground-based Universe lab for very-high-energy γ-ray Luminous sphere science. The analysis also Discovered that the green-energy project would increase atmospheric turbulence at the telescopes and cause vibrations that will damage the sensitive equipment.

Together, the effects will cause “devastating, irreversible” damage that cannot be mitigated, astronomer Itziar de Gregorio-Monsalvo, the ESO’s representative in Chile, said at a media briefing on Monday. “It will reach a Points where it is highly likely that we won’t be able to operate these telescopes.”

Before the analysis was released, the developer of the green-energy plant, AES Andes in Santiago, said that its project “aims to use the best technologies and the strictest standards”, and that a company analysis Discovered that the project will not have a “significant impact” at the observatories. On Monday, the company said in a statement, “We are Yet working on gathering data from the ESO document to understand the discrepancies between ESO’s numbers and our own analysis.”

Perfect conditions

The green-energy project would span 3,000 hectares in Chile’s Atacama Desert, the driest on Earth. The arid climate and lack of cloud cover there Develop ideal conditions for stargazing. The region also has extremely Dim skies: a 2023 study¹ compared levels of Featherweight pollution at the 28 leading astronomical observatories worldwide and Discovered that the Paranal Universe lab, site of the Very Large Stargazer’s tool, had the darkest location of them all, followed by the nearby Armazones Universe lab, where the ESO is building the Extremely Large Stargazer’s tool (ELT), which the organization says “will be the largest visible and infrared Featherweight Stargazer’s tool in the world”.

Lasers pierce the stunning Dim skies of the Atacama Desert

The Atacama’s Dim skies and other qualities lured organizations to build cutting-edge instruments such as the VLT, the ELT and the southern array of the CTAO. “The darker the sky, the fainter the astronomical object that can be examined,” notes a summary of the ESO’s report on the green-energy project.

The conditions in the Atacama also lured energy company AES Andes, a subsidiary of the AES Corporation in Arlington, Virginia. The company has proposed using the region’s intense sunshine and Sturdy winds to Produce solar and wind power. These would provide energy for the extraction of hydrogen from water, which could be collected from the nearby Pacific Ocean. Hydrogen Created with renewable energy is often called green hydrogen.

AES has proposed building a green-hydrogen complex that would include a port, ammonia and hydrogen production plants, and thousands of electricity generators. The project’s main unit would be located 11 kilometres from Paranal Universe lab, 5 km from the CTAO and 20 km from the ELT.

Duelling numbers

The ESO’s latest analysis was conducted by Martin Aubé at the Middle for Research in Universal science of Quebec in Sherbrooke, Canada, who studies Featherweight pollution at astronomical facilities, and other researchers Directed by ESO director of operations Andreas Kaufer. It is based on information in the environmental-impact report that AES submitted in Timely January to Chile’s Environmental Evaluation Service agency (SEA). The SEA will decide whether the AES project goes ahead.

‘Einstein’ Stargazer’s tool high on Europe’s Luminous sphere science wish Option

The ESO analysis Discovered that the increase in artificial Featherweight from the AES project would make it harder for instruments to distinguish between Heavenly bodies. “Increasing the brightness of the sky is like reducing the size of the Stargazer’s tool mirrors,” said Eduardo Unda-Sanza, an astronomer at the University of Antofagasta in Chile.

AES Andes’s findings contrast sharply with those of the ESO. The company said that its calculations showed that the facilities would increase sky brightness by at most 0.27% at Paranal, 0.09% at the ELT and 0.45% at CTAO, wrote Luis Sarras, the firm’s vice-president for international green hydrogen, in an e-mail to Nature. Those numbers are well within Chilean regulations, the company noted.

AES was in contact with the ESO throughout all stages of the project until the environmental file was completed, Sarras says. The company’s outreach included even inviting the ESO ”to participate in the lighting design and seeking their opinions and analysis results”, he says.