October 31 this year would be a “once in a blue moon” event. Halloween nights are scary enough but add in a rare moon from a supernatural film, it gets scarier. On Halloween night, a rare full moon is expected to be visible to the whole world. This would be the first time since World War II the moon would be visible everywhere and not just in some parts.
Full moons are separated by 29 days, while most months are 30 or 31 days long; so it is possible to fit two full moons in a single month. This happens every two and a half years, on average.
However, the last time the Blue Moon was spotted on Halloween day, that is, October 31, was in the year 1944.
However contrary to its name, a Blue Moon usually looks like it would on any other day. The date of a full moon, all by itself, doesn’t affect the moon’s color. The moon on October 31 will be pearly-gray, as usual.
Inputs: India Today