By JULIE CUNNINGHAM
(Franklin County, MA) This Halloween, trick or treaters will be delighted to a rare full moon, called the Blue Moon, which will be the second full moon of October. Blue Moons are the term used for the second full moon of a calendar month. According to NASA Science, the Blue Moon occurs every two and a half years because the lunar calendar and the Gregorian Calendar, the calendar named after Pope Gregory XIII which is the most widely used calendar in the world, are not in sync. The lunar calendar runs on 29 day cycles, while the Gregorian calendar breaks months into either 30 or 31 days, with the exception of February.