Roughly once every two and a half years, a strange phenomenon occurs in the night sky – the blue moon. This year, there is the Blue Moon of July. Apparently, “once in a blue moon” doesn’t stand for some far away, inconceivable date. The event actually does happen.
When the term first came into use, it meant, well – almost never. But since then, people realized that the strange astrological event does take place every now and then. So the meaning gradually evolved into what we know today to be very rarely, seldom, or plainly in an absurdly long time.
When did you see your last blue moon?
Well, here’s the trick – you’re tempted to think of a moon that actually is the color blue. But if you don’t live near an active volcano, or where very specific kinds of forest fires burn, then you probably did not see such a selenic color ever. What is really meant by the scientific term of Blue Moon today is no more than a mere calendar trick. Let me explain:
Normally, a full moon comes about every 29 days. Considering the length of a month to be about thirty days, than we can safely say that a year has twelve full moons. Well, except when it doesn’t. Like, take 1946 for example. That year there were thirteen moons. Such a year is called a “Blue Moon Year.” The Sky & Telescope magazine issue from March 1946 mixed up the phrase Blue Moon with the actual calendar quirk. The name stuck and the rest is history.
How can there be thirteen moons in a year? Well, logically, when two squeeze in a single month. The last Blue Moon was in August 2012. Now, it is set to happen again in this very month of July. The first full moon will be tonight (the 2nd of July) and the second, the one that actually bares the name Blue Moon, will come in on – you guessed it, 2+29 – July 31st.
So, no actual blue moon will take place, I’m sorry if the name is misleading, go complain to Sky & Telescope. Now if you actually want to see a blue moon, besides the multitude of filtered photos that can be found online, the natural blue hued moon occurs in areas where there have been volcanic eruptions – like when Krakatoa exploded in 1883, there was a blue moon in many parts of the earth. Yet, not only a blue moon, but also a blue sun and bluish clouds.
Doesn’t all this seem surreal? Well, it only happens once in a blue moon, so we’re probably safe.
Image source: www.sierraclub.org