Here’s the Recent Blue Moon—And What a Blue Moon Actually Is

You might have heard rumours going around of a blue moon on July 31^st, but did you see it and do you know what exactly it is?

Probably everyone’s heard the term “once in a blue moon”, so you can probably guess that a blue moon happens relatively rarely. There’s actually two types of blue moons, but unfortunately, neither of them are really blue.

One type of blue moon refers to the second full moon in just one calendar month. This kind of blue moon is the one the world experienced on Friday, since there was a full moon on July 2^nd and another one snuck in on the last day of July. This type of blue moon happens at least once every two or three years.

Friday's blue moon above the gorgeous Okanagan hills. (Photo Credit: KelownaNow.com)

The other kind of blue moon is a bit more complicated. Basically, different seasons, defined in astronomy from solstice to equinox or vice versa, generally have three full moons. When an extra one squeaks in, the third full moon is referred to as a blue moon.

It’s a little disappointing that blue moons aren’t actually blue, but there can be blue-coloured moons. This happens when dust or smoke particles of a specific size are in the air, scattering blue light. Red moons are much more common, and B.C. certainly sees those time to time in the wildfire season.

One last fun fact: once every 19 years or so, February doesn’t have a full moon with its short length. In the years when February doesn’t have a full moon, two different months actually have two full moons. Watch out for this phenomenon in 2018.

This mornings setting moon-this is a reminder that tonight is a full moon. The second full moon in the month of July. This rare occurrence is also known as a blue moon hence the phrase "Once in a Blue Moon" #bluemoon #explorekelowna #fullmoon #exploreeverything #exploreokanagan @kettle.valley

A photo posted by Stephen Wells (@hr.wells) on Jul 31, 2015 at 5:56am PDT

From last nights #bluemoon #nightphotography shoot in#Kelowna BC. #bluemoon2015#astrophotography#kelownanow#explorekelowna#tourism#brittishcolumbia#canada#canon70D

A photo posted by Marketing In Motion Inc. (@marketinginmotion) on Aug 1, 2015 at 3:10pm PDT

In honor of tonight's 'Blue Moon,' astronaut Scott Kelly aboard the International Space Station posted this image and wrote, "TGIF Here's a preview of tonight's rare celestial surprise. #BlueMoon on the rise. #YearInSpace." 'Once in a Blue Moon' typically means rare or absurd. This year, it means tonight! According to modIn honor of tonight's 'Blue Moon, astronaut Scott Kelly aboard the International Space Station posted this image and wrote, "TGIF Here's a preview of tonight's rare celestial surprise. #BlueMoon on the rise. #YearInSpace." 'Once in a Blue Moon' typically means rare or absurd. This year, it means tonight! According to modern folklore, the second full moon in a month is a "Blue Moon." But of course that doesn't necessarily mean it's blue. Step outside at sunset, look east and see what color presents itself. Image Credit: NASA #nasa #iss #spacestation #space #isscrew #NASABeyond #moon #bluemoon #science #TGIF Here's a preview of tonight's rare celestial surprise. #BlueMoon on the rise. #YearInSpace B55F8243-3CE1-4E4F-94D4-BE4CD3849E12ern folklore, the second full moon in a month is a "Blue Moon." But of course that doesn't mean it's necessarily blue. Step outside at sunset, look east and see what color presents itself. Image Credit: NASA #nasa #iss #spacestation #space #isscrew #NASABeyond #moon #bluemoon #science #TGIF Here's a preview of tonight's rare celestial surprise. #BlueMoon on the rise. #YearInSpace

A photo posted by NASA (@nasa) on Jul 31, 2015 at 10:35am PDT