Blue moon for Halloween November 4, 2020 Lunar notesIt was hard to miss the moon this week. Daniel Schiavo caught this one over the Chesapeake Bay on Friday, October 30. Meanwhile, hobgoblins trick-or-treated on Halloween, Saturday, October 31, under a blue moon, the second full moon of the month. According to the Farmer’s Almanac, a full moon occurs on Halloween every 19 years. However, Saturday’s full moon appeared in all time zones, and that hasn’t happened since 1944.