Chile’s Atacama Desert is one of the darkest spots on Earth, a crown jewel for astronomers who flock to study the origins of the universe in this inhospitable desert along the Pacific coast. A rare confluence of factors makes the Atacama an ideal home for some of the world’s biggest astronomical projects – dry climate, high altitude and, crucially, isolation from the light pollution of civilization. But that may not be the case for much longer, leading scientists warned in a letter to Chile’s government released Tuesday. A company is pressing ahead with plans to construct a giant renewable energy complex in sight of one of Earth’s most productive astronomical facilities.