A Blue Moon rises over Burlington Tuesday night.
The term ‘Blue Moon’ was originally defined as the third full moon in a four moon season. An error printed in a 1943 issue of “Sky & Telescope” magazine mistakenly defined a blue moon as the second full moon in a single month. The definition stuck.
Tuesday’s blue moon is a ‘technical’ Blue Moon. It is the third full moon in a four-full-moon season. The ‘Blue Moon’ rule was originally detailed in a 1937 edition of Maine Farmers’ Almanac.
Blue Moons occur infrequently, the next Blue Moon will not occur until 2015.