Free Astronomy Magazine March-April 2025

4 MARCH-APRIL 2025 ASTRO PUBLISHING industrial megaproject is planned to be located just 5 to 11 kilometres from telescopes at Paranal, which would cause irreparable damage to astronomical observations, in partic- ular due to light pollution emitted throughout the project’s operational life. Relocating the complex would save one of Earth’s last truly pristine dark skies. Since its inauguration in 1999, Paranal Observatory, built and operated by the European Southern Observatory (ESO), has led to sig- nificant astronomy breakthroughs, such as the first image of an exo- planet and confirming the acceler- ated expansion of the Universe. The Nobel Prize in Physics in 2020 was awarded for research on the su- permassive black hole at the centre of the Milky Way, in which Paranal telescopes were instrumental. The observatory is a key asset for astronomers worldwide, including those in Chile, which has seen its as- tronomical community grow sub- stantially in the last decades. Additionally, the nearby Cerro Arma- zones hosts the construction of ESO’s Extremely Large Telescope (ELT), the world’s biggest telescope of its kind — a revolutionary facility that will dramatically change what we know about our Universe. World’s darkest and clearest skies at risk O n December 24 th , AES Andes, a subsidiary of the US power company AES Corporation, submitted a project for a massive in- dustrial complex for environmental impact assessment. This complex threatens the pristine skies above ESO’s Paranal Observatory in Chile’s Atacama Desert, the darkest and clearest of any astronomical obser- vatory in the world. A study by Falchi and collaborators, published in 2023 in Monthly Notices of the Royal As- tronomical Society , compared light pollution at all 28 major astronomi- cal observatories, finding Paranal to be the darkest site among them. The by ESO Francisco Rodríguez Bárbara Ferreira