Did you get a chance to see the blue moon? (July 31, 2015)
You missed out on something absolutely incredible! A blue moon is indescribably rare—in fact—it’s one of the most rare astronomical phenomenon in the entire universe! Every 700 years, gravitational perturbations cause the moon’s orbit to become highly elliptical, resulting in a closer than normal lunar perigee. Reflected sunlight bounces off Earth and paints the moon an odd blueish hue—much like Rayleigh scattering, which explains why the sky is blue, as well.
Glad you missed the blue moon?
Haha! Did you believe me? Don’t lie! Damn I’m good.
**Truth be told** I took this image with a blue planetary filter, which you can read more about—here. Blue moons are not as rare as I described and they are not that special. If you visually investigated a couple of full moon photographs (side-by-side), you wouldn’t be able to distinguish a blue moon from a regular full moon, unless, of course, the blue moon was actually blue.
So…what the hell is a legitimate blue moon?
I don’t know.
Well, I do. Kind of. Sort of.
Personally, I always described a blue moon as the second full moon in a given month. It’s easy to remember and explain, but is this technically right? Nope. Well…kind of. This mistake can be traced back to a Sky & Telescope Magazine article, which was published in the 1940’s. The article proved to be an oversimplification and it’s ultimately incorrect. Damn!
A true blue moon involves astronomical seasons and the number of full moons within each season, which is normally 3. If a particular astronomical season is scheduled to have 4 full moons (instead of 3)—the third full moon is considered “blue”.