|
Posted by baalke on May 30, 2007, 2:20 pm
Please log in for more thread options
http://science.nasa.gov/headlines/y2007/30may_bluemoon.htm
Blue Moon over North America
NASA Science News
May 30, 2007
May 30, 2007: At 9:04 pm Eastern Daylight Time on May 31st, the full
moon over North America will turn blue.
Not really. But it will be the second full moon of May and, according
to
folklore, that makes it a Blue Moon.
If you told a person in Shakespeare's day that something happens "once
in a Blue Moon" they would attach no astronomical meaning to the
statement. Blue moon simply meant rare or absurd, like making a date
for
"the Twelfth of Never."
But "meaning is a slippery substance," writes
Philip Hiscock of the Dept. of Folklore, Memorial University of
Newfoundland. "The phrase 'Blue Moon' has been around a long time,
well
over 400 years, and during that time its meaning has shifted."
The modern definition sprang up in the 1940s. In those days the Maine
Farmer's Almanac offered a definition of Blue Moon so convoluted even
professional astronomers struggled to understand it. It involved
factors
such as ecclesiastical dates of Easter and Lent, tropical years, and
the
timing of seasons according to the dynamical mean sun. Aiming to
explain
blue moons to the layman, Sky & Telescope published an article in 1946
entitled "Once in a Blue Moon." The author James Hugh Pruett
(1886-1955)
cited the 1937 Maine almanac and opined that the "second [full moon]
in
a month, so I interpret it, is called Blue Moon."
This was not correct, but at least it could be understood. And thus
the
modern Blue Moon was born. A detailed account of the story may be
found
here <http://skytonight.com/observing/objects/moon/3304131.html>.
Surveying the last four centuries of literature and folklore, "I have
counted six different meanings which have been carried by the term,"
recounts Hiscock. In song, for instance, Blue Moons are a symbol of
loneliness; when love conquers all, the Blue Moon turns gold. (See old
Elvis records for more information.) "This makes discussion of the
term
a little complicated," he says.
One complication is that the Moon can turn genuinely blue, as shown in
this photo taken by Tom King of Watauga, Texas:
http://science.nasa.gov/headlines/y2007/images/bluemoon/King2.jpg
Above: A blue Moon photographed in October 2003 by Tom King of
Watauga,
Texas. "Here is a picture <images/bluemoon/King_gray.jpg> from a
different night provided as a sanity check to assure you that my moon
shots do not always have this blue hue," says King.
"I had never paid any real attention to the term 'Blue Moon' until one
October evening in 2003," he recalls. "I had my telescope set up in
the
backyard and the moon began rising in the east with a strange blue
tint
I had not seen before."
The cause of the blue was probably tiny droplets of water in the air.
"The air was damp and heavy with moisture," notes King. When water
droplets are about 1 micron (one millionth of a meter) in diameter,
they
strongly scatter red and green light while allowing other colors to
pass. A white moonbeam passing through such a misty cloud turns blue.
Clouds of ice crystals, fine-grained sand, volcanic ash or smoke from
forest fires can have the same effect. "The key," notes atmospheric
optics expert Les Cowley, "is that the airborne particles should all
be
of very similar size, a micron or so in diameter." Only then do they
scatter the correct wavelengths of moonlight and act as a blue filter.
There are other reasons for blue Moons, he notes. "Our eyes have
automatic 'white balances' just like digital cameras. Go outdoors from
a
cozy cabin lit by an oil lamp (yellow light) and the Moon will appear
blue until your eyes adjust."
What kind of Blue Moon will you see this week? There's only one way to
find out!
|
|
Posted by N:dlzc D:aol T:com \(dlzc\) on May 30, 2007, 8:40 pm
Please log in for more thread options
Dear baalke:
> http://science.nasa.gov/headlines/y2007/30may_bluemoon.htm
>
> Blue Moon over North America
> NASA Science News
> May 30, 2007
>
> May 30, 2007: At 9:04 pm Eastern Daylight Time on May
> 31st, the full moon over North America will turn blue.
>
> Not really. But it will be the second full moon of May and,
> according to folklore, that makes it a Blue Moon.
Actually no, this was covered on NPR. In 1946 a scientific
publication published that the second full moon in a month was a
blue moon. It meant at the time, the fourth full moon of a
*season*. Someone didn't pay attention.
David A. Smith
|
|
Posted by Llanzlan Klazmon the 15th on May 30, 2007, 11:39 pm
Please log in for more thread options $7g3.201895@newsfe14.phx:
> Dear baalke:
>
>> http://science.nasa.gov/headlines/y2007/30may_bluemoon.htm
>>
>> Blue Moon over North America
>> NASA Science News
>> May 30, 2007
>>
>> May 30, 2007: At 9:04 pm Eastern Daylight Time on May
>> 31st, the full moon over North America will turn blue.
>>
>> Not really. But it will be the second full moon of May and,
>> according to folklore, that makes it a Blue Moon.
>
> Actually no, this was covered on NPR. In 1946 a scientific
> publication published that the second full moon in a month was a
> blue moon. It meant at the time, the fourth full moon of a
> *season*. Someone didn't pay attention.
>
> David A. Smith
>
Sure but who is to say which definition is correct. It is a matter of
convention after all:
http://en.wikipedia.org/wiki/Blue_moon
Actually I miss out this month as the full moon is at 01:03 on 1st of June
for this time zone. We do get a second full moon for the month of June on
the 30th instead.
Klazmon.
>
>
|
|
Posted by Greg D. Moore \(Strider\) on May 31, 2007, 8:02 am
Please log in for more thread options > Dear baalke:
>
>> http://science.nasa.gov/headlines/y2007/30may_bluemoon.htm
>>
>> Blue Moon over North America
>> NASA Science News
>> May 30, 2007
>>
>> May 30, 2007: At 9:04 pm Eastern Daylight Time on May
>> 31st, the full moon over North America will turn blue.
>>
>> Not really. But it will be the second full moon of May and,
>> according to folklore, that makes it a Blue Moon.
>
> Actually no, this was covered on NPR. In 1946 a scientific publication
> published that the second full moon in a month was a blue moon. It meant
> at the time, the fourth full moon of a *season*. Someone didn't pay
> attention.
>
Right, and as the REST of the article goes into those details, sounds like
someone wasn't paying attention....
> David A. Smith
>
--
Greg Moore
SQL Server DBA Consulting Remote and Onsite available!
Email: sql (at) greenms.com http://www.greenms.com/sqlserver.html
|
| Similar Threads | Posted | | Comet May Have Exploded Over North America 13,000 Years Ago | August 16, 2007, 5:26 pm |
| Blue Ring Discovered Around Uranus | April 6, 2006, 8:59 pm |
| Blue Ring Discovered Around Uranus | April 7, 2006, 11:47 am |
| North polar geysers on Mars? | July 27, 2007, 11:28 am |
| SMART-1 Image: An Oblique Look on the North Lunar Far West | August 9, 2006, 12:05 pm |
| Cassini Images Mammoth Cloud Engulfing Titan's North Pole | February 1, 2007, 12:20 pm |
| Re: No ice on Moon? | October 23, 2006, 11:01 am |
| Re: No ice on Moon? | October 24, 2006, 11:23 pm |
| Moon Storms | December 7, 2005, 5:12 pm |
| Definition of 'moon' | August 24, 2006, 1:49 pm |
|
XML Sitemap