Just as the sun slips behind the Chilean Andes, it seemed to send up a tiny emerald flare. The photograph, taken from Cerro Pachón in Chile by NOIRLab Audiovisual Ambassador Petr Horálek, captures a classic but elusive atmospheric trick of the…

Just as the sun slips behind the Chilean Andes, it seemed to send up a tiny emerald flare. The photograph, taken from Cerro Pachón in Chile by NOIRLab Audiovisual Ambassador Petr Horálek, captures a classic but elusive atmospheric trick of the…