Moon

Just How Rare Is an Actual Blue Moon? [VIDEO]
Just How Rare Is an Actual Blue Moon? [VIDEO]
Just How Rare Is an Actual Blue Moon? [VIDEO]
Saying something only happens “once in a blue moon” typically means it’s extremely rare. True blue moons — defined as the second full moon in a month — aren’t actually that uncommon, but if you don’t catch the one on Aug. 31, it’ll be three years before you get another chance.