If you are keen about the unusual astronomical phenomenon, lunar events and more, then you need to watch out tonight for the rare blue moon on the horizon.
'Once in a blue moon' is not just a phrase that's used for occasional events.
It is also a unusual astronomical phenomenon that occurs when a full moon occurs twice in a calendar month.

see more here: http://duketunde..com/2015/07/rare-blue-moon-on-horizon-tonight.html

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