By ZOE MOORE, ABC News (NEW YORK) — On Halloween, the sky will be lit up by a rare blue moon on the spookiest night of the year.While it is called a blue moon, the moon won’t actually appear blue. The phrase refers to the time when a second full moon occurs in one month.According to NASA, a blue moon occurs about seven times every 19 years.This year, there will be a full moon on Oct. 1 and on Oct. 31.The last blue moon appeared March 31, 2018, according to Earth Sky.Copyright © 2020, ABC Audio. All rights reserved.
