Full Moon: Tomorrow's Blue Moon Not Happening Again Until 2015

Tomorrow's full moon, scheduled for Tuesday (Aug. 20), will be known as as Blue Moon due to the fact that this will be the third full moon in the season, according to various reports.

History shows us that a Blue Moon is technically the third full moon in a four-full-moon season. Yahoo News notes, via a 1946 article titled "Sky & Telescope" magazine, that the Blue Moon was previously mistaken as the second full moon of the season, and unfortunately, the definition stuck at the time.

Yet this annual August moon has also become known as the Full Sturgeon Moon because of a large fish named sturgeon that can easily be caught during this time of the year, a name that allegedly came from bodies of water including the Great Lakes and Lake Champlain.

Full moons occur approximately every 29.5 days. This is the proper time period for the moon to be facing opposite the sun, according to meteorologists. Though the moon is usually full, sometimes a lunar eclipse occurs and may cause a dark disk instead of a full white circle.

Blue Moons however are certainly rare. Various reports note that the next one isn't coming until 2015. Make sure you step outside for a look tomorrow!