Jessica Booth
January 31, 2018 11:17 am
9600GTX / Getty Images

If you woke up early to get a glimpse of the super blood blue moon in the sky, chances are good that you got a pretty amazing show. Social media is full of photos of the super rare lunar event, and it’s actually all anyone is really talking about. If you missed this one, you’re going to have to wait a long time to see another super blood blue moon — like over 20 years at least. Fortunately, the moon does a lot of other cool stuff. A blue moon helps to make up a super blood blue moon (clearly!), and while it’s also uncommon, it’s not quite as rare. So when is the next blue moon?

You’ve heard of the saying, “once in a blue moon,” right? It refers to a moment that doesn’t happen very often, and yes, it got its name from the actual blue moon lunar event. In other words, a blue moon doesn’t happen often; it certainly doesn’t happen as often as a full moon or a supermoon. It’s not as rare as it seems, though — they happen once every 2.7 years.

There are actually two different definitions of a blue moon.

The term was originally used to refer to a season that has four full moons instead of the usual three, known as seasonal blue moons. The most popular blue moon definition right now refers to when there are two full moons in one month. The second definition came about from an error made by amateur astronomer James Hugh Pruett. It may have been a mistake on his part, but the definition spread quickly and even ended up appearing as an answer in the 1986 version of the board game Trivial Pursuit. So today, it’s considered a second definition instead of a mixup.

According to Space.com,

Okay…so when can you expect to see the next one? 2018 is proving to be a very special year for lunar events, because there are actually two full moons in both January and March. This is sometimes called a double blue moon. That second blue moon is happening on March 31st, 2018 and is considered a “calendar” blue moon, because there are two full moons in March. This blue moon won’t be visible to everyone, so check out this Moon Phase page to see if you’ll be able to spot it.

As for the next seasonal blue moon, that will be May 18th, 2019. That refers to the original definition: a three-month season where there are four full moons.

That means you might not have too long to wait before your next blue moon! And even if you miss the one happening this March, the next is only about two years away.

Advertisement