SCOTT DETROW, HOST:
The night skies above the Chilean desert are the best in the world to see deep into space, but light pollution from a planned industrial project could change that, as John Bartlett reports.
JOHN BARTLETT, BYLINE: When night falls over the Paranal Observatory, which operates one of the world's most powerful telescopes, the skies above are dusted with brilliant constellations and nebulae.
ITZIAR DE GREGORIO-MONSALVO: (Speaking Spanish).
BARTLETT: The Very Large Telescope, or VLT, at Paranal began operations in 1998 and has taken readings which have won three Nobel prizes. It is operated by the European Southern Observatory, led by Spanish astronomer Itziar de Gregorio (ph).
DE GREGORIO-MONSALVO: (Speaking Spanish).
BARTLETT: De Gregorio explains that the unique confluence of factors - clear nights, low atmospheric pressures and rare darkness - make this the best place in the world to observe the night sky, but this could soon change. Energy company, AES Andes, has put forward plans for the country's first industrial-scale green hydrogen and ammonia processing plant. It would be built just 7 miles from the observatory.
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BARTLETT: But a new telescope is already under construction. All of this could be rendered ineffective if the nearby industrial project is green lit. Towering over the Atacama Desert on Cerro Armazones, 3,000 meters above sea level, is the 80-meter steel dome of the Extremely Large Telescope, the largest and most powerful ever built. I'm standing inside the structure, which is about 60% complete, on a narrow concrete walkway. In front of me, light will be bounced between five mirrors mounted on a central console, the largest of which will be 39 meters across. By the end of this decade, this telescope will allow us to peer well beyond our solar system to identify Earth-like exoplanets which might support life.
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BARTLETT: The ELT will be 20 times more powerful than the VLT at Paranal. The telescope's main mirror will be made up of 798 individual hexagonal segments, painstakingly polished in a sealed laboratory upon arrival from Europe.
DE GREGORIO-MONSALVO: (Speaking Spanish).
BARTLETT: "If the light pollution increases significantly here, it would be equivalent to having a much smaller mirror. It means that the reasons why the ELT was built no longer makes sense," de Gregorio tells me as we shelter from the wind and sun in the bowels of the concrete structure. "Chile's astronomical prowess will be lost."
(SOUNDBITE OF MUSIC)
BANDERSEBAS: (Singing in Spanish).
BARTLETT: By day, the astronomers and technicians at Paranal have a band, Bandersebas, which practices in a soundproof room. There's a swimming pool and cacti are arranged beneath a glass dome, ringed by an echoey cement walkway.
(SOUNDBITE OF METAL SQUEAKING)
BARTLETT: When the last ray of sunlight touches a sensor on the residence's roof, a rose-like bunch of pleated fabric unfurls, sealing all light inside. And with that, the night shift begins.
MARCELA ESPINOZA: OK. (Speaking Spanish).
BARTLETT: Marcela Espinoza is a Chilean astronomer working at the base.
ESPINOZA: (Speaking Spanish).
BARTLETT: "The light pollution is going to be terrible for the observatory," Espinoza tells me. "And that's what worries us - because we have this natural laboratory to study the universe. It could be catastrophic." A report by Chile's environmental regulator recommended moving the proposed site, and a decision is expected soon. Ultimately, if the astronomical community is unsuccessful in getting the project moved, our last great window into the universe could be lost forever. For NPR News, I'm John Bartlett at Paranal Observatory, Chile. Transcript provided by NPR, Copyright NPR.
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