Sorry to spoil the fun but, blue moons, in reality are not actually blue in color, but is just an alias for the second full moon in a single calendar month, which is an uncanny phenomenon.
July 2015 will sport two full moons, the second being a blue moon. The first full moon will be on second July while the second full moon will be on 31st in the same month. The last blue moon took place in 2012, when both September and August boasted two full moons in specific time zones. Another blue moon is bound to take place on Jan 2018.
The definition of a blue moon as the second full moon in a calendar month is a modern invention. Only a few years ago, blue moons were the name given to the third of four full moons in a single season.
Stating ‘once in a blue moon’ is obviously a strange phrase. But with many different ways to terma full moon blue, they are relatively common. The only truly rare blue moon is the one which is an actual blue-colored moon, which isn’t an impossibility.
Certain conditions in the atmosphere can impart a blue tinge to the moon, most likely of which is the result of a volcanic eruption on a large scale. In 1883, when the Indonesian volcano Krakatoa violently erupted, plumes of ash descended on the top of Earth’s atmosphere, making the moon appear blue.
High-altitude layers of ash particles absorbed light from the red end of the spectrum, causing moonbeams to appear blue and green. Bluish moons persisted for several years.
According volcanologist Scott Rowland of the University of Hawaii, the phenomenon also caused the sun to appear lavender in color, and precipitated “such vivid red sunsets that fire engines were called out in New York, Poughkeepsie, and New Haven to quench the apparent conflagration.”
The Farmer’s Almanac refers to the full moons of July as thunder moons, which get their name due to the month’s behavior to show bring intense afternoon rain storms. The almanac also calls the first full moon a buck moon, as June marks the first time of the year when young dear begin to sprout antlers.