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 ...
There are very special cases, when the sky is very clear and exceptionally transparent, that a green flash can be glimpsed just as the very topmost part of the sun is rising or setting. When you ...