Get us in your inbox

Photograph: Filip Wolak

Everything you need to know about tomorrow’s rare blue moon

Will Gleason
Written by
Will Gleason

If anything even remotely odd happens to you tomorrow night, be sure to have the phrase “once in a blue moon” at the ready. The rare, lunar event is set to take over the sky when the sun sets. Here’s what you need to know.

What is a blue moon?
These days, a blue moon is most commonly defined as the second moon in a month that has two full moons. The lunar calendar doesn’t line up with ours perfectly, so every once in a while one month gets two full moons. An old definition of the event is the third full moon in a calendar season that has four full moons. These moons generally don’t overlap, and the first definition is the one most often used now. 

When does the blue moon happen?
July’s second full moon will rise at 8:14pm on Friday. It won’t be completely full at that point (it will have reached his apex at 6:43am) but that’s as close as we’re going to get.

Will the moon be blue?
No, girl. “Blue moon” is just a term. Moons can occasionally appear blue, but that’s only caused by dust or particles in the atmosphere. The last time that happened was around the Mt. St. Helens eruption in 1980 and Mount Pinatubo eruption in 1991.

How rare is this thing?
They happen every three years. The last blue moon happened in August 2012, and the next one will happen in January 2018.

How do I celebrate?
You could make some Blue Moon Ice Cream. Or hit up the Full Moon Festival on Saturday.

Is this what Pocahontas was singing about with that whole wolf crying to the Blue Corn Moon thing?

Popular on Time Out

    Latest news