An undated file image shows a full moon in the night sky. (Photo by: A&G Reporter/AGF/Universal Images Group via Getty Images) Halloween night will be extra spooky this year, as a rare lunar event is set to light up the night sky — and it only happens “once in a blue moon.”A full moon will appear on Oct.
31, 2020, Farmers’ Almanac said. Such an event occurring on Halloween only happens every 18 to 19 years, so it will be an extra-special spectacle, according to the periodical.It will also be the second full moon of the month, and therefore, is called a “blue moon.” It won’t appear blue in color, though.