Everyone now, “Blue moon; You saw me standing alone; Without a dream in my heart; Without a love of my own.”

But did you know that a blue moon isn’t just a legendary Elvis Presley song (with a quirky scene in the original Grease movie set to it)? It’s actually a meteorological phenomenon. Unfortunately, the name attributed to this phenomenon doesn’t mean that the moon appears to have a blue-ish hue (though sometimes it does).

A blue moon, at least in modern days, is the term given to the second full moon in calendar month. This lunar timing only occurs once every two and a half years or so, and your next chance to catch a blue moon is August 31st, 2012 — next month.

According to Live Science, tomorrow night, August 1st, is the first full moon of the month, with the moon completing its cycle and becoming full again on the last day of the month.

According to Sky and Telescope, the idea that the second full moon in a calendar month is the blue moon is actually incorrect, but they say “trying to correct this (mis)interpretation is like trying to stuff a genie back into its bottle”.

So get out tomorrow night to enjoy the 1st full moon of the month and then enjoy the blue moon on August 31st — and hey, maybe you should even crack open a Blue Moon to enjoy as you gaze into the night sky.

Main photo credit: snappydessy/Flickr