It only happens every once in a – well – blue moon, and it’s going to be visible over our fair city tonight.
Despite what the title suggests, the moon won’t actually be blue. A blue moon occurs when it’s the second full moon of the month, an event that only happens every three or four years. The first full moon was on July 2.
NASA says the term “blue moon” has Shakespearean roots.
“If you told a person in Shakespeare’s day that something happens “once in a Blue Moon” they would attach no astronomical meaning to the statement. Blue moon simply meant rare or absurd, like making a date for “the Twelfth of Never.” Since then, however, its meaning has shifted.”
And it’s the perfect evening for a full moon, with Environment Canada reporting perfectly clear skies tonight and into the weekend.
— NASA (@NASA) July 31, 2015