Blue Moon: A Rare Sight Tuesday Night

Before you start turning pages in your favorite astronomy book, let’s be clear. It’s true; the most common usage for Blue Moon (besides referring to the 1934 song by Richard Rodgers and Lorenz Hart covered by many including Billie Holiday, Elvis Presley, The Marcels and even Sha-Na-Na in the movie Grease) refers to the second full moon in a single month.

Although Tuesday’s full moon will be just the first full moon in August (typically, when a Blue Moon occurs, there are two full moons per month), there are several other meanings for the term, according to Space.com. 

A less common usage dates back to at least 1937 according to Space.com, in which a Blue Moon is the third of four full moons each season (where a season is the time from the equinox to the solstice, or from the solstice to the equinox).

Tuesday’s Blue Moon, then, is what’s known as a seasonal blue moon: The third this season (that’s summer, if Monday’s fall-like temperatures have you confused).  It will rise to its peak at 9:45 p.m., according to The Weather Channel.

The rarest Blue Moon is a phenomenon in which the  moon actually looks … wait for it … Yes, blue. This is caused by particles in the air—often ash and dust caused by a volcano or, as in this instance described on Spaceweather.com, a major forest fire.

"Blue moon
You saw me standing alone
Without a dream in my heart
Without a love on my own."