ASTRONOMY PICTURE

OF THE DAY

JUNE 4, 2014

A Green Flash from the Sun

EXPLANATION

Many think it is just a myth. Others think it is true but its cause isn’t known. Adventurers pride themselves on having seen it. It’s a green flash from the Sun. The truth is the green flash does exist and its cause is well understood. Just as the setting Sun disappears completely from view, a last glimmer appears startlingly green. The effect is typically visible only from locations with a low, distant horizon, and lasts just a few seconds. A green flash is also visible for a rising Sun, but takes better timing to spot. A dramatic green flash, as well as an even more rare red flash, was caught in the above photograph recently observed during a sunset visible from the Observatorio del Roque de Los Muchachos in the Canary Islands, Spain. The Sun itself does not turn partly green or red—the effect is caused by layers of the Earth’s atmosphere acting like a prism.

Image Credit & Copyright

Daniel López (El Cielo de Canarias)