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Credit: Roberto Porto
Monday, August 3, 2015: Astrophotographer Roberto Porto sent in a photo of the Blue Moon showing a 22-degree halo, taken in Castilla (Castile), Spain,…Read More »

on July 31, 2015. The term "Blue Moon" refers to a 2nd full moon in a month. The 22-degree halo around the moon results from ice crystals in the atmosphere, the hexagonal structure of which refract the moonlight to the observer.

— Tom Chao   Less «
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