How appropriate that 2020's Halloween Night will feature a rare lunar event.

Just like the image above, visuals that often come to mind for Halloween Night include a full moon. Maybe sometimes obscured by fog or some clouds. Even though this imagery is pretty commonplace, it is pretty rare that it actually happens.

October 31 will not only feature a full moon (which is very rare), but it will also be a "blue moon", which is also fairly rare. While it won't actually be blue, a "blue moon" means it is the second full moon within a calendar month. We got our first full moon on October 1, and bookending October 2020 will be a second full moon to add a little extra spookiness to Halloween night.

You've probably heard the phrase "once in a Blue Moon", suggesting something is uncommon or rare. How uncommon is it? Space.com says they happen on average about once every 2.7 years. So, if it isn't actually blue, why call it a "Blue Moon"? Space.com also explains that it comes from an old English term that means "betrayer". Being most months feature only one full moon, a second full moon can be deceptive, and is subject to the uneven way in which our calendar is laid out.

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While Blue Moons are rare, a full moon on Halloween is a much more uncommon occurrence. Just how rare is a full moon on Halloween? Well, almanac.com says it only happens every 18-19 years. The last time we saw one was 2001, and the next ones we'll see will be in 2039, 2058, and 2077; so take this one in, because the next one won't come around for quite some time.

Add the traditional full moon urban legends, folklore, and superstitions to the fact that it will be on Halloween night - in 2020 to boot, and I'm sure your mind can run wild with bad scary movie plots. It also welcomes some costume ideas. Werewolf, anyone?

If you like the Halloween full moon aesthetic and can't wait for the next one, here is some kind of good news. It will look almost "full" sooner than 2039. The folks at farmersalmanac.com report that while it won't be an official 100% full moon, 2029 and 2031 will feature almost full moons (98% illuminated), with the full moon falling just after Halloween (November 2) in 2029 and just before Halloween (October 30) in 2031. As far as looks go, you might not even be able to tell.

Whatever you're doing this Halloween, hopefully you enjoy it safely. Just don't forget to look up and take in a scene we won't see again until 2039.