Green flash at La Silla

ESO Photo Ambassador Petr Horálek has photographed his colleague Babak Tafreshi as he photographs an unusual atmospheric phenomenon known as the Green Flash. As the light of the setting Sun is bent through the atmosphere, it is as if it was passing through a prism. Usually we only see the red part of the spectrum, so the Sun appears red, but when conditions are just right, you can see a brief flash of green on top of the setting Sun. The enlargement in the insert shows the effect more clearly. Horálek and Tafreshi are both members of ESO's Fulldome Expedition team, in Chile to take stunning photographs for use in planetarium presentations.