Dark secrets Stargazing heaven put at risk by energy plant

In the Atacama desert, the driest non-polar region on Earth, the sky shines when the sun sets. Up in the arid hills 130km south of the Chilean city of Antofagasta, comets burn brightly and flawless trails of stars and nebulae streak the night sky.

- By John Bartlett SANTIAGO

So complete is the darkness that Indigenous peoples staring up at these skies contemplated the dark spots in between the stars - finding the forms of animals and ancestors in the perfect darkness beyond. These are the dark- est, clearest skies for observation in the world, and they have propelled Chile to become the world's astronomical powerhouse. But they are under imme- diate threat, astronomers are warning.

In December, the energy company AES Andes put forward plans for the country's first industrial-scale green hydrogen and ammonia processing plant, known as the Inna project. The proposed 3,000-hectare facility will generate solar and wind energy, feed- ing excess into the national grid. The suggested main site is about 12km from one of Chile's most important observatories.

Last month, Chile's environmental regulator criticised the project's proposed location, but let a deadline to strike down the $10bn project elapse. The threat to Chile's observa- tories remains.

The astronomical community says the size and scale of the project - which will need to be illuminated at night for safety - as well as light reflected off roofs, solar panels and machinery, will seriously affect readings.