I heard that the next full moon will be on Oct. 31. How often is there a full moon on Halloween?
Belinda S., Chicago
There will, indeed, be a full moon this Halloween, the city’s first Halloween full moon since 2001. It will be October’s second full moon, the Harvest full moon occurring Oct. 1. While Halloween scenes typically depict witches and goblins flying across the face of the full moon, the moon can be in any phase on Halloween. Astronomer Dan Joyce, a member of the Chicago Astronomical Society, tells us that the average frequency of any lunar phase occurring on a particular date is twice in any 59-year period. The year’s Halloween full moon will be followed by four more this century in 2039, 2058, 2077, and 2096.