Once in a blue moon, we get to experience a blue moon. If we look up at tonight’s sky, we will have that opportunity.
According to NASA, a blue moon is a term coined when there is a second moon within a calendar month. There was a full moon on Aug. 1 and the second one will rise this evening at 7:03 p.m.
NASA says moongazers should not expect a blue hue on tonight’s moon; it is not physically different than any other full moon.
Two blue moons in a month typically occurs every 2.7 years, according to the Huffington Post. The last blue moon was on Dec. 31, 2009, and the next won't occur until July of 2015.
According to the Farmer's Almanac, the "two moons in one month" definition of a blue moon is actually fairly modern, since the widespread adoption of the standard calendar. In folklore, a blue moon was the third full moon of a season that had four.
It is unknown where the term 'blue' came from to describe the rare moon.
Are you doing something special to celebrate the blue moon?