segunda-feira, 20 de março de 2017

Astronomy picture of the day - 2017 March 20 - The Aurora Tree

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The Aurora Tree 
Image Credit & Copyright: Alyn Wallace Photography
Explanation: Yes, but can your tree do this? Pictured is a visual coincidence between the dark branches of a nearby tree and bright glow of a distant aurora. The beauty of the aurora -- combined with how it seemed to mimic a treeright nearby -- mesmerized the photographer to such a degree that he momentarily forgot to take pictures. When viewed at the right angle, it seemed that this tree had aurora for leaves! Fortunately, before the aurora morphed into adifferent overall shape, he came to his senses and capture the awe-inspiring momentary coincidence. Typically triggered by solar explosions, aurora are caused by high energy electrons impacting the Earth's atmosphere around 150 kilometers up. The unusual Earth-sky collaboration was witnessed earlier this month in Iceland.