There are two astronomical definitions of a Blue Moon; both are a type of Full Moon. When the Moon very rarely actually looks blue, it’s because of a certain size dust particles in the atmosphere.
The next Blue Moons
|2015||Friday, July 31|
|2016||Saturday, May 21|
Once in a blue moon means very rarely. But just how rare depends on your definition.
In astronomy, Blue Moon is defined as either the third full moon of an astronomical season with four full moons or the second full moon in a calendar month.
Such a blue Moon (second full Moon in single calendar month) will next occur on Friday, July 31, 2015 at 10:43 am UTC.
Contrary to popular belief, a blue moon is not actually blue in color. Blue moon is a term that is used to describe the third full moon…
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