Waiting for a blue moon? Tuesday could be your night

Regardless of the rival definitions for a blue moon, Tuesday's full moon should be spectacular.

Tim Hornyak
Crave freelancer Tim Hornyak is the author of "Loving the Machine: The Art and Science of Japanese Robots." He has been writing about Japanese culture and technology for a decade. E-mail Tim.
Tim Hornyak
2 min read
Blue moon by Tim Hornyak/CNET
With a bit of in-camera color adjustment, you can capture a blue moon like this one from November 2012. Tim Hornyak/CNET

If you've been waiting for a rarity to come along, keep your gaze skyward. Tuesday's moon is not only full, it's a blue moon.

That is, if you disregard a commonly accepted definition of a blue moon as being a second full moon in a calendar month. A real blue moon, according to purists, is the third full moon in a season of four full moons, which is one more than the standard.

The confusion has been attributed to a 1946 article in "Sky & Telescope" magazine defining a blue moon as the second in a month. The publication has since described that as "a mistake."

The error has stuck, however, and so many sky-watchers and sources like Britannica will only call the second full moon in a calendar month a blue moon.

You can call it an "alternative blue moon" if you like, but the rival moons are equally rare. Seven out of 19 years will feature two full moons in a month as well as four in a season, according to EarthSky.

But you can also call Tuesday's moon a Full Sturgeon Moon because some Native American tribes caught the fish at this time of year.

If you're of an agricultural bent, you can call it the Green Corn Moon or the Grain Moon, reflecting the growth of such plants.

Another name, according to Space.com, is "Full Red Moon, because the weather and atmospheric conditions during this season can often make the moon look reddish when it rises through a haze."

Whatever you fancy, get out there Tuesday night and drink in Earth's stunning natural satellite. For your listening pleasure, I suggest Radiolab's wonderful podcast of actor Liev Schreiber reading Italo Calvino's tale "The Distance of the Moon."


Tuesday's blue moon in all its glory (pictures)

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