Once in a 'blue moon' on Tuesday...but there's a catch

Once in a 'blue moon' on Tuesday...but there's a catch

Summary: On Tuesday night you can see a relatively rare event - a blue moon. But there's a good chance you'll be disappointed.

TOPICS: Nasa / Space

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  • On Thursday Aug. 20, a relatively rare event will take place in the skies above you—it's called a blue moon.

    Why it occurs is somewhat complicated. A full moon, when no shadow from Earth covers the lunar body, happens every 29.5 days. Normally this means that there will be 12 full moons a year and three per season. However, once every 2.7 years there will be an extra full moon in one of the four seasons. When this occurs, the third of the four full moons is called a "blue moon." This was devised by Native Americans who gave names to each full moon and then passed it on to the first European settlers.

    People have been confused as to what a blue moon really is after an expert mistakenly told "Sky & Telescope" magazine in 1943 that the 1937 Maine Farmers Almanac revealed that a blue moon occurs when any particular month had two full moons. A widely read 1946 article in Sky & Telescope confimed this.

    However, the magazine did not rest on its laurels. Editors examined more than 40 editions of the Maine Farmers Almanac from 1819 to 1962 and found references to several blue moons—and all were based on an extra full moon per season—not the two full moons in a month version.

    BUT WAIT. Before you plan to watch the full moon, you'll probably be very disappointed. (continue)

  • The colors you'll see from the moon might be orange, red, and its normal yellow. The infrequency of  blue moons originated the expression, "once in a blue moon."


Topic: Nasa / Space

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  • Yawn.

    Why is this even a story? It's a full moon, that's it. By accident of the calendar, you get two in one month. You don't "celebrate" "Blue Sunday", if we get an extra Sunday.
    • that's why it's a story

      some people are out there thinking the moon will be blue.
    • Well, at least it's not yet another "story" about

      one huge mega-corporation suing another.
      • Not so fast.

        Rumor has it that IBM ("Big Blue") has filed a law suit in this matter. ;-)
    • Actually, the Article Says That's a Misconception

      According to the article a blue moon is not the rare event of two full moons in the same month, but rather, the rare event of four full moons in the same season, but specifically the third of the four.

      It's interesting that the article would contain a correction on this while also making the technical mistake of identifying the dark part of the Moon as the Earth's shadow. When the Earth's shadow crosses the Moon, that is a lunar eclipse. The normal dark part of the Moon is the shadowed side of the Moon, that is, the side away from the Sun. When we see a full Moon, we see only the part of the Moon facing the Sun and none of the part facing away from the Sun.
      • Can't make up his mind

        Yes, he makes a big deal about it not being the second full moon in the month, and then he goes and says exactly that on his second slide!

        "The colors you'll see from the moon might be orange, red, and its normal yellow. A blue moon is actually the second full moon of the month - not that common and is the origin of the expression, "once in a blue moon.""
      • Wellllll . . .

        . . . here's the thing. On the first panel, he says that the definition of a blue moon being the second full moon in a single month was created in error. Then, on the second panel, he goes right on and says that's exactly what it is.

        Thankfully, he does provide a link to an article that explains that, while the older definition of the third full moon in a season with four is the correct one, the modern one is also considered acceptable through common usage.

        This does lend well to your secondary point, however, that this article is in serious need of an editing job.
        • Interesting.

          It looks like someone went in and edited the caption on the second panel to remove the "second full moon" reference. The first panel still insinuates that the phases of the moon are dictated by the shadow of the Earth, however. (Unless he's saying that a full moon that gets eclipsed doesn't count? Hmmm . . .)
      • As soon as I read that, I stopped reading...

        ...since the author has no business writing about subjects he doesn't understand.
  • Today there is another rare event...

    This year August the 31st is on Friday. Next time August the 31st is on Friday will be in 2018!
    How is that for a story?
    • Think that is a story?

      "Friday the 13th" fell on a Tuesday this month. Fortunately, it falls on a Friday next month.
  • The 20th is Tuesday

  • earth shadow has nothing to do with it

    "A full moon, when no shadow from Earth covers the lunar body, happens every 29.5 days."

    Just wow. That sounds an awful lot like the author thinks a half moon is caused by earth shadow.
    Adam Russell