The next full moon won’t be the biggest or brightest of 2020, but it could be the spookiest. If, you know, you’re into that stuff. That’s because on Oct. 31, we will see the first full moon to fall on Halloween since 2001. We won’t see another one until 2039. We’ll also be seeing a so-called “blue moon,” meaning it will be the second full moon of the month (it also was full on Oct.