Blue Moon

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22nd Aug 2021

While the Moon may not actually be turning blue, make sure to take a look at the Blue Moon on 22 August. 

This Full Moon will be a Blue Moon because it is the third Full Moon in an astronomical season. Astronomical seasons are defined by the time between equinoxes and solstices – there are roughly four astronomical seasons every year.

Between the Summer Solstice (21 June) and the Autumn Equinox (22 September), there happen to be four Full Moons. The Full Moon in August is the third of those four Full Moons, which means it is the Blue Moon. Even though ‘once in a Blue Moon’ might mean that something is rare, Blue Moons actually happen every two or three years.

Why Is It Called a Blue Moon?

The historical origins of the term and its two definitions are shrouded in a bit of mystery.  Some believe that the term “blue moon” meaning something rare may have originated from when smoke and ashes after a volcanic eruption turned the Moon blue. Others trace the term’s origin to over 400 years ago – folklorist Philip Hiscock has suggested that invoking the Blue Moon once meant that something was absurd and would never happen.

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