Blue Moon

• Blue Moon

July 31, 2015 could see a rare phenomenon - the so-called "blue moon". The last time this happened in 2012, and the next time - only in 2018.

The term "blue moon" scientists understand the second full moon in a month. Usually in 12 full moons occur within a year - one a month. However, the blue moon occurs every 2.7 years - a rare "blue".

A small selection of photos of the moon in different countries.

Blue Moon

the moon really blue hue can be observed very rarely necessary conditions for this - the turbidity of the atmosphere with ash, dust or smoke, for example, as a result of a volcanic eruption or a severe forest fire.

MANILA, Philippines, July 31, 2015. (Photo J.V. Noriega)

Blue Moon

The name "Blue Moon" is given because of its rarity: in English the phrase "Once in a blue moon" is an idiom and is used to mean "so rare that you can remember when."

This time, despite the name, its color the moon has not changed. Somerset, England, July 30, 2015. (Photo by Matt Cardy):

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Washington, DC, July 31, 2015. (Photo by Bill Ingalls):

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The Blue Moon in Rome, Italy, July 31, 2015. (Photo by Max Rossi):

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The Moon and the plane in Cairo, May 2, 2015. (Photo by Amr Abdallah Dalsh):

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The full moon over Istanbul, Turkey, May 5, 2015. (Photo: Osman Orsal):

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The Blue Moon in New Jersey on July 31, 2015. (Photo: Julio Cortez):

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The moon in China, May 9, 2015. (Photo: Reuters | Stringer):

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The Moon in London, on June 30, 2015. (Photo by Toby Melville):

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The moon rises above the church on the Greek island of Santorini, July 1, 2015. (Photo: Cathal McNaughton):

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Switzerland, July 1, 2015. (Photo by Denis Balibouse):

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The moon and the Statue of Liberty in New York, July 31, 2015. (Photo by Eduardo Munoz):

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The Blue Moon in New York on July 31, 2015. (Photo by Eduardo Munoz):

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Blue Moon, England, July 31, 2015. (Photo by Eddie Keogh):

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Somerset, England, July 30, 2015. (Photo by Matt Cardy):

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The moon behind the dome of the Capitol in Washington, DC, July 31, 2015. (Photo by Bill Ingalls):

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The Blue Moon over Lake Michigan, USA, 31 July 2015. (Photo by John Hart):

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Blue Moon, Wisconsin, July 31, 2015. (Photo by Dan Young):

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Blue Moon, California, July 31, 2015. (Photo by Nick Ut):

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Full Moon in New Jersey, July 1, 2015. (Photo: Julio Cortez):

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The Blue Moon in New Jersey on July 31, 2015. (Photo: Julio Cortez):

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The Blue Moon in New Jersey on July 31, 2015. (Photo: Julio Cortez):

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Full Moon and the Kazan Kremlin, July 29, 2015. (Photo by Denis Tyrin):

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